BlogEcommerce / Design & UXApril 1st, 2024 · 16 min read

Key Aspects of Ecom­merce UX Design

Ecommerce UX design
Article by Santiago Melluso

Defin­ing Ecom­merce UX Design

This one is about eCom­merce web design. More specif­i­cal­ly, about UX design. User Expe­ri­ence (UX) is always men­tioned along­side its beau­ti­ful sib­ling UI. But ecom­merce UX design is a dif­fer­ent thing. 

UI refers to the spe­cif­ic visu­al touch­point or asset the user inter­acts with. It’s com­mon­ly described as the look and feel”, you could say the cos­met­ics, includ­ing col­or, typog­ra­phy, icons, but­tons, or spac­ing, among others.

While UI focus­es on aes­thet­ics and the over­all feel of the design, user expe­ri­ence is a much broad­er sub­ject. It includes every aspect of the end user’s inter­ac­tion with a com­pa­ny, its ser­vices and prod­ucts. This means your phys­i­cal store expe­ri­ence, your sup­port, brand, vibe, sto­ry­telling and the actu­al jour­ney from dis­cov­er­ing a prod­uct to pur­chas­ing it. 

In ecom­merce it cer­tain­ly includes your site’s usabil­i­ty, acces­si­bil­i­ty and how plea­sur­able or not it is for a user to inter­act with it, accord­ing to the site’s load or wait time, the infor­ma­tion avail­able and its functionality.

It needs to be (…) use­ful, usable, and delight­ful, and not nec­es­sar­i­ly in that order, but we try to encap­su­late all three of those. If your site isn’t use­ful, no one is going to come to it. If it’s not usable, peo­ple have a hard time inter­act­ing with it. And last­ly, if it’s not delight­ful, the loy­al­ty of your prod­uct is not going to be what it could be.

Jason Broughton, head of UX for Zappos

Key aspects of ecom­merce UX design

eCom­merce design has evolved but, in the con­text of ecom­merce ux design, the key aspects to con­sid­er in order to deliv­er an ide­al expe­ri­ence remain. Here’s an overview of the main ones:

User-cen­tric

It may sound obvi­ous, but a site that is focused on the peo­ple it’s intend­ed for, is more like­ly to offer a bet­ter expe­ri­ence. This includes not los­ing sight of the real goal of the peo­ple who use your prod­uct, or in this case, your site. Case in point:

user centric UX design

User expe­ri­ence design often los­es sight of the actu­al user.

When sites opti­mize so much for the behav­ior that it wants to influ­ence next (col­lect­ing an email address, mov­ing peo­ple into a fun­nel), the rea­son that peo­ple come to the site in the first place can get over­looked (or buried under pop-ups).

There’s a con­tin­u­al bal­anc­ing act between user expe­ri­ence and user exploita­tion: what is best for the user and what is best for the com­pa­ny. A design­er has to nav­i­gate that line.

Mar­ke­toon­ist

User-cen­tric nav­i­ga­tion is about plac­ing the user at the heart of the design process. Imag­ine you enter a large super­mar­ket for the first time; a clear lay­out, well-signed aisles, and an acces­si­ble infor­ma­tion desk can make your shop­ping expe­ri­ence smooth and pleas­ant. It’s the same in a web­site: user-cen­tric nav­i­ga­tion aims to cre­ate a clear path through an ecom­merce site, mak­ing it effort­less for users to find what they’re search­ing for.

At the heart of user-cen­tric nav­i­ga­tion lies sim­plic­i­ty. Sim­ple, intu­itive menus, straight­for­ward cat­e­gories, and a search bar that actu­al­ly under­stands what you’re look­ing for – these are the cor­ner­stones of user-cen­tric nav­i­ga­tion. It’s about reduc­ing com­plex­i­ty, not by remov­ing valu­able infor­ma­tion, but by orga­niz­ing it in a way that feels nat­ur­al to the user.

Con­sis­ten­cy in nav­i­ga­tion cre­ates a sense of famil­iar­i­ty and com­fort. Just as you come to know the lay­out of your favorite local store, con­sis­tent nav­i­ga­tion on an ecom­merce site means users know where to find what they need, every time they vis­it. This pre­dictabil­i­ty reduces frus­tra­tion and builds con­fi­dence, encour­ag­ing users to explore deep­er into the site.

Anoth­er key aspect of user-cen­tric nav­i­ga­tion in ecom­merce UX design is empa­thy – under­stand­ing the user’s jour­ney, antic­i­pat­ing their needs, and craft­ing an expe­ri­ence that feels as nat­ur­al and intu­itive as explor­ing your favorite store by keep­ing it sim­ple, con­sis­tent and easy to navigate.

Accept­abil­i­ty: Fast or furious

Gen­er­al­ly speak­ing, web­site accept­abil­i­ty” refers to how sat­is­fac­to­ry or usable a web­site is from the user’s per­spec­tive. Specif­i­cal­ly, it means how long your users will be will­ing to wait for a web­site to load before poten­tial­ly los­ing interest. 

A faster-load­ing site enhances user expe­ri­ence, increas­es engage­ment, and is more like­ly to retain vis­i­tors, which is cru­cial for e‑commerce suc­cess. Con­verse­ly, a slow load­ing web­site will most like­ly make users feel frus­trat­ed, and leave. Game over. 

Slow sites= Bad UX

There­fore, every sec­ond counts, espe­cial­ly on mobile, and quite lit­er­al­ly too.

Ecommerce UX Design

How fast your web­site loads is crit­i­cal but often a com­plete­ly ignored ele­ment in any online busi­ness and that includes search mar­ket­ing and search engine opti­mi­sa­tion. And that includes page load times on mobile devices: The aver­age time it takes to ful­ly load a mobile land­ing page is 22 sec­onds, accord­ing to a new analy­sis. Yet 53% of vis­its are aban­doned if a mobile site takes longer than three sec­onds to load”.

Daniel An — Google/​SOASTA research 2017

Ecommerce UX Design

Respon­sive: Tiny screens need big performance

This one should be old advice by now, but you’d be amazed how many brands still fail at it:

The rise of smart­phones as the pri­ma­ry device for inter­net access has sig­nif­i­cant­ly shift­ed con­sumer behav­ior, mak­ing mobile respon­sive­ness not just advan­ta­geous, but imper­a­tive for ecom­merce success.

A mobile-respon­sive site ensures a seam­less expe­ri­ence across all devices, whether it’s a desk­top, tablet, or smart­phone. This flu­id­i­ty is cru­cial as con­sumers often switch devices dur­ing their pur­chase jour­ney. A site that adjusts con­tent lay­out, images, and nav­i­ga­tion to fit the screen size and ori­en­ta­tion of the device not only enhances usabil­i­ty but also con­veys pro­fes­sion­al­ism and atten­tive­ness to cus­tomer needs. A site that doesn’t can be a problem.

Ecommerce UX Design

(Clever) jokes aside, adopt­ing a mobile-first approach is not shrink­ing a web­site to fit a small­er screen, but rethink­ing and pri­or­i­tiz­ing con­tent and fea­tures that are most impor­tant to mobile users. This might mean sim­pli­fy­ing menus, enhanc­ing touch inter­ac­tions, and ensur­ing that calls to action are promi­nent­ly dis­played. A mobile-first design acknowl­edges that space is at a pre­mi­um and focus­es on deliv­er­ing a stream­lined, intu­itive user experience.

And a fast one. As men­tioned, a delay of just a few sec­onds can lead to sig­nif­i­cant drops in engage­ment and sales. More­over, evi­dence indi­cates that mobile delays could cause a 44% increase in heart rate, indi­cat­ing a lev­el of stress com­pa­ra­ble to watch­ing a hor­ror movie. Which are fine if you like them, but if they’re good, they are prob­a­bly quite stressful.

Anoth­er thing that speeds things up, and also hap­pens to help users make deci­sions faster, which in turn helps them feel bet­ter, is sim­plic­i­ty. A clean, unclut­tered lay­out with easy-to-read fonts and ample space can dra­mat­i­cal­ly improve the mobile shop­ping experience.

Respon­sive­ness is a must and not hav­ing it is hav­ing two of your birds killed with one stone. Mobile-friend­ly sites not only cater to a wide audi­ence but also pos­i­tive­ly impact SEO, as Google pri­or­i­tizes respon­sive design over non-respon­sive sites.

Read more here

High qual­i­ty means high quality

Visu­al appeal is para­mount in ecom­merce UX design. High-qual­i­ty images and detailed prod­uct descrip­tions sig­nif­i­cant­ly impact cus­tomer deci­sion-mak­ing and gen­er­al feel. 

For exam­ple, high-res­o­lu­tion images that offer mul­ti­ple views and zoom-in func­tion­al­i­ty can mim­ic the in-store expe­ri­ence, allow­ing cus­tomers to close­ly inspect prod­ucts. Make sure your web­site has a sol­id CDN to deliv­er images fast, so qual­i­ty doesn’t tax speed and performance.

An image is worth a thou­sand words, but that doesn’t mean words don’t mat­ter. Com­pre­hen­sive and accu­rate descrip­tions pro­vide nec­es­sary details to make an informed pur­chase deci­sion. They should high­light key fea­tures, ben­e­fits, and any unique sell­ing points, address­ing poten­tial ques­tions or con­cerns. They are also an excel­lent oppor­tu­ni­ty to con­sol­i­date your brand style, voice and tone. Extra UX points if they make your users laugh. Laugh brings good feels. 

Improv­ing your nav­i­ga­tion leads to bet­ter con­ver­sion rates

You know how we use nav­i­gate” to talk about how we deal with dif­fi­cult sit­u­a­tions? Nav­i­gate com­plex­i­ties, chal­lenges, hard con­ver­sa­tions? Yes, well, exact­ly the oppo­site. Think about nav­i­ga­tion nav­i­ga­tion. As in sail­ing with calm waters, havin’ a good time. 

And just as a well-chart­ed map is cru­cial for a suc­cess­ful voy­age, a well-designed nav­i­ga­tion sys­tem ensures users always know where they are, where they can go next, and how to return to a pre­vi­ous­ly vis­it­ed page, which allows them to find their way with­out get­ting lost in the depths of the site. Ok, per­haps it’s time to drop the nau­ti­cal references. 

(User-friend­ly nav­i­ga­tion) is a cor­ner­stone of effec­tive ecom­merce web­site design. Nav­i­ga­tion is not sta­t­ic. It’s live and dynam­ic and must be reg­u­lar­ly updat­ed to pro­mote your best cat­e­gories. Dynam­ic and reg­u­lar­ly updat­ed nav­i­ga­tion ensures that users can eas­i­ly find and explore your best cat­e­gories. Opt for an unclut­tered design with smooth tran­si­tions between pages and Imple­ment a clean and intu­itive nav­i­ga­tion struc­ture to increase user engage­ment and sat­is­fac­tion, which is the fuel for con­ver­sion rates.

Our eCom­merce Web­site Design 101

The key to sim­ple and intu­itive nav­i­ga­tion lies in under­stand­ing the user’s mind­set. Users come to your site with spe­cif­ic goals, whether it’s find­ing a prod­uct, learn­ing more about your ser­vices, or con­tact­ing your team. Your nav­i­ga­tion should cater to these needs with clear, descrip­tive labels and a log­i­cal hier­ar­chy that mir­rors the thought process of your users. Drop­down menus, used spar­ing­ly, can help orga­nize con­tent into man­age­able cat­e­gories with­out over­whelm­ing users. Bread­crumb trails and sticky menus enhance nav­i­ga­tion by pro­vid­ing con­text and quick access to oth­er sec­tions of the site, respec­tive­ly. Search bars and fil­ter options can help them find exact­ly what they are look­ing for.

Effec­tive Search UX Best Practices

A pow­er­ful search func­tion is instru­men­tal for a great user expe­ri­ence on any ecom­merce site. It’s what may turn a poten­tial­ly frus­trat­ing expe­ri­ence into a sat­is­fy­ing one, by allow­ing users to find exact­ly what they’re look­ing for with min­i­mal effort.

It’s not just about hav­ing a search bar, but about pri­or­i­tiz­ing search func­tion­al­i­ty to make shop­ping more per­son­al­ized and effi­cient in order to enhance user experience. 

Some ways to do so include:

-Mak­ing the search bar eas­i­ly acces­si­ble, promi­nent­ly placed so users don’t have to hunt for it.

-Help­ing users with place­hold­er prompts and exam­ples to guide their search.

- Adding auto-com­plete func­tion­al­i­ty to reduce the user’s effort and to help guide their search in real-time with sug­ges­tions of prod­ucts, cat­e­gories or content.

-Using advanced search fil­ters to help users nar­row down their search results based on spe­cif­ic cri­te­ria such as size, col­or, price range, or rating.

Last­ly, con­sid­er inte­grat­ing ecom­merce AI pow­ered tools like Advanced­Com­mercee or Algo­lia for a more pow­er­ful and per­son­al­ized search expe­ri­ence. These plat­forms can ana­lyze user behav­ior to deliv­er search results that are not just rel­e­vant but also tai­lored to each vis­i­tor’s pref­er­ences and pre­vi­ous inter­ac­tions with your site. But pro­ceed with caution.

secrets behind successful ecommerce UX design

This is not good for UX.

Easy Check­out Process in ecom­merce UX design:

There is your user, ready to buy the prod­ucts found in your easy-to-nav­i­gate, user-friend­ly, respon­sive web­site. At check­out, excite­ment and antic­i­pa­tion turn to frus­tra­tion; the first require­ment is to cre­ate an account. This feels unnec­es­sary and time con­sum­ing. Still deter­mined, but some­what uncom­fort­able, the user pro­ceeds, only to be faced with a seem­ing­ly end­less form that asks for details that are total­ly irrel­e­vant to the purchase.

Reluc­tant­ly, the user fills it out but then dis­cov­ers an unex­pect­ed ship­ping fee, which increas­es the total cost sig­nif­i­cant­ly. Hop­ing to get it over with as soon as pos­si­ble, the user tries to final­ize the pur­chase, when an error mes­sage appears, as cryp­tic as ancient runes, offer­ing no clue as to what went wrong or how to cor­rect it. Each attempt to pro­ceed results in the same frus­trat­ing out­come, with no sup­port or guid­ance in sight. After many irri­tat­ing tries, the user is about to final­ize the pur­chase, but learns their pre­ferred pay­ment method is not accept­ed, the icing on a bit­ter cake that tastes like crap.

The bad news: 

Exhaust­ed and dis­ap­point­ed, the user aban­dons their cart, leav­ing behind the items, and any like­li­hood of ever return­ing. A frus­trat­ing check­out process is a bar­ri­er to con­ver­sion, erod­ing trust and dri­ving poten­tial cus­tomers into the arms of competitors. 

The good news: 

Fix­ing check­out usabil­i­ty issues alone can boost con­ver­sion rates by 35%. 

The goal is to min­i­mize fric­tion and make the trans­ac­tion as quick and effort­less as pos­si­ble, gen­er­al­ly ensur­ing every­one (or at least, most peo­ple) will find options con­ve­nient to them.

Here are some best prac­tices in ecom­merce UX Design:

  • Offer Guest Check­out: Allow users to make a pur­chase with­out cre­at­ing an account.
  • Trans­par­ent Costs: Dis­play all costs upfront, includ­ing ship­ping and tax­es, to avoid sur­pris­es at checkout.
  • Sim­pli­fy Forms: Keep form fill­ing require­ments to a min­i­mum and only include nec­es­sary fields in check­out forms and con­sid­er using aut­ofill to speed up the process.
  • Diverse Pay­ment Options: Pro­vide a vari­ety of pay­ment meth­ods to accom­mo­date dif­fer­ent user preferences.
  • Clear Error Mes­sages: Offer spe­cif­ic, help­ful error mes­sages and guid­ance on how to resolve them.

And a recap of check­out process big no no’s in ecom­merce UX Design

  • Hid­den Costs: Sur­pris­ing cus­tomers with addi­tion­al costs (such as ship­ping or tax­es) at the check­out can cause frus­tra­tion and loss of trust. No one likes an ambush.
  • Com­plex Forms: Long and com­pli­cat­ed forms, espe­cial­ly with unnec­es­sary fields, can over­whelm and deter users from com­plet­ing their purchase.
  • Lack of Pay­ment Options: Offer­ing lim­it­ed pay­ment meth­ods can turn away cus­tomers who pre­fer dif­fer­ent pay­ment options.
  • Forced Account Cre­ation: Some­times it’s inevitable, but requir­ing users to cre­ate an account before they can make a pur­chase can be a sig­nif­i­cant bar­ri­er, lead­ing to cart abandonment.
  • No Error Guid­ance: Fail­ing to pro­vide clear, spe­cif­ic feed­back on what went wrong (e.g., incor­rect card details) can leave users con­fused and unable to proceed.
Improving your navigation leads to better conversion rates

TL;DR:Best Prac­tices in Ecom­merce UX Design

And here’s anoth­er quick recap, this time on best prac­tices in ecom­merce UX design.

  • Fast Load Times: Users expect quick, seam­less expe­ri­ences. Slow load­ing times can lead to frus­tra­tion and high bounce rates, so opti­miz­ing for speed is crucial.
  • User-Cen­tric Nav­i­ga­tion: Remem­ber Sim­pli­fy the user’s jour­ney through intu­itive and eas­i­ly nav­i­ga­ble menus. Clear cat­e­go­riza­tion and a search func­tion are indis­pens­able for help­ing users find prod­ucts swiftly.
  • Mobile Respon­sive­ness: With an increas­ing num­ber of shop­pers using mobile devices, ensur­ing your ecom­merce site is ful­ly respon­sive is non-nego­tiable for an opti­mal UX.
  • High-Qual­i­ty Images and Descrip­tions: Prod­uct images and descrip­tions should be detailed and high-qual­i­ty, pro­vid­ing users with a clear under­stand­ing of what they are purchasing.
  • Search: Reduce user frus­tra­tion and improve the shop­ping expe­ri­ence with an intu­itive search with auto-com­plete, fil­ters, and sug­ges­tions to ensure users can quick­ly find exact­ly what they’re look­ing for.
  • Sim­ple and Intu­itive Nav­i­ga­tion: Design a clear and log­i­cal site nav­i­ga­tion to keep users engaged and reduce bounce rates, with an unclut­tered lay­out, well-labeled cat­e­gories and a vis­i­ble search bar.
  • Easy Check­out Process: Sim­pli­fy and opti­mize the check­out process to min­i­mize fric­tion and reduce cart abandonment. 

Ecom­merce UX Design Trends

Mobile-First UX Design for Ecommerce

The shift towards mobile-first UX design is more than a trend; it’s a neces­si­ty. With an increas­ing num­ber of con­sumers turn­ing to their smart­phones for shop­ping, ensur­ing your ecom­merce site is opti­mized for mobile is cru­cial. This involves design­ing with mobile users in mind from the out­set, focus­ing on aspects like:

  • Clear, Easy Ways to Search: Ensur­ing the search func­tion­al­i­ty is promi­nent and user-friend­ly on small­er screens.
  • Mobile-Opti­mized Images: Images should be high qual­i­ty yet opti­mized for quick load­ing times.
  • Acces­si­ble Font Sizes and Con­trasts: Text should be easy to read, and but­tons easy to tap, accom­mo­dat­ing the small­er space of mobile screens.
  • Tai­lored Check­out Process: Stream­lin­ing the check­out process to remove any poten­tial bar­ri­ers for mobile users.

Per­son­al­iza­tion in Ecom­merce UX Design

Per­son­al­iza­tion is becom­ing increas­ing­ly impor­tant in cre­at­ing a unique and engag­ing user expe­ri­ence. By lever­ag­ing data and insights into cus­tomer behav­ior, ecom­merce sites can offer per­son­al­ized rec­om­men­da­tions, con­tent, and offers that res­onate with indi­vid­ual users. This lev­el of cus­tomiza­tion not only enhances the user expe­ri­ence but also encour­ages loy­al­ty and repeat business.

Expe­ri­ences that tell a story

Ecom­merce is no longer just a home­page with a ban­ner and a few fea­tured items. It takes a lot more to stand out. The trend is to shift from sim­ple trans­ac­tion­al sites to immer­sive expe­ri­ences that tell a brand’s sto­ry. What used to be slow and expen­sive to devel­op is now just a cou­ple of days of work away thanks to no code tools like Shogun, Livesto­ry, Zmags, and Sty­la, which allow for the inte­gra­tion of rich media, inter­ac­tive ele­ments, and sto­ry­telling tech­niques that cap­ti­vate users and dif­fer­en­ti­ate brands in crowd­ed marketplaces.

Scarci­ty and FOMO

Using scarci­ty and FOMO can be effec­tive in dri­ving urgency and con­ver­sions, but it’s impor­tant to approach this trend eth­i­cal­ly with­out resort­ing to tricks, mis­in­for­ma­tion or dark pat­terns. Real-time updates like Only X left in stock” or X peo­ple are view­ing this prod­uct” can cre­ate a sense of urgency with­out resort­ing to manip­u­la­tive tac­tics. The key is to use these ele­ments truth­ful­ly and spar­ing­ly to enhance the shop­ping expe­ri­ence rather than to exploit users.

Tips for Ecom­merce UX Design

In addi­tion to keep­ing up with trends, here are some key tips to con­sid­er in ecom­merce UX design:

Sup­port is experience

Pro­vid­ing robust cus­tomer sup­port, includ­ing FAQs, live chat, and easy-to-find con­tact infor­ma­tion, can sig­nif­i­cant­ly enhance the user experience.

UX is objec­tive and measurable

What­ev­er you do to improve your cus­tomer expe­ri­ence can be mea­sured. There­fore it is not an entire­ly sub­jec­tive field and you should treat it as an iter­a­tive process of mea­sur­able improve­ments. Use ana­lyt­ics and user feed­back to con­tin­u­ous­ly mea­sure and improve UX. Small, iter­a­tive changes can lead to sig­nif­i­cant improve­ments in user sat­is­fac­tion and con­ver­sion rates.

Con­ver­sion rate opti­miza­tion: a reg­u­lar practice

Speak­ing of mea­sur­ing, be con­sis­tent in your attempts to improve your prod­uct page, look­ing for mar­gin­al increas­es on con­ver­sion ratio per vis­i­tor through small tweaks. Some exam­ples of ele­ments to test and opti­mize regularly:

  • Text, size and col­or of your add to cart button
  • Gallery style and image optimization
  • Bet­ter descriptions 
  • Test­ing out dif­fer­ent pric­ing design options
  • Includ­ing or exclud­ing reviews, etc

Brand your entire experience

Loy­al buy­ers go through three basic stages dur­ing their shop­ping jour­ney. First they dis­cov­er the brand, then they take action (the action of shop­ping), and then they should be nudged to become active ampli­fiers of your brand. Make sure you trea­sure and reward stage 3.

Brand Your Entire Expe­ri­ence: From dis­cov­ery through pur­chase and post-sale, every inter­ac­tion should reflect your brand’s val­ues and style. Per­son­al touch­es, such as brand­ed pack­ag­ing, thought­ful con­fir­ma­tion emails, encour­ag­ing users to leave reviews or social media shares, offer­ing guides, tips or any oth­er post-sale effort that improves a user’s expe­ri­ence, can help you turn cus­tomers into brand ambassadors.

Make sure it works

Every­thing is bro­ken, every­where, all the time. Here are a few things to keep a close eye on:

  • Load­ing times: Mon­i­tor per­for­mance with tools like GTmetrix or Pingdom
  • Check­out process: Reg­u­lar­ly test to ensure it’s fast and flawless
  • Account sec­tion: Make sure it includes infor­ma­tion on ship­ping sta­tus, easy returns, sup­port and help..

Run your own UX research

  • You don’t need to be a high pro­file retail­er or have a mas­sive bud­get to run a bit of research and gain insights into user behav­ior. Here are a few quick tips:
  • The way we inter­act online is con­stant­ly chang­ing. Stay informed about the lat­est usabil­i­ty trends and con­ven­tions by sub­scrib­ing to Bay­mard, or the Nielsen Nor­man Group.
  • Find your most loy­al cus­tomers and invite five or ten to try out designs, col­lec­tions, ideas, or pro­mo­tions. You’ll be sur­prised how excit­ed they can be and the valu­able insights you can draw from their hon­est and blunt feedback.
  • Keep an eye on your ana­lyt­ics and look for behav­ioral pat­terns and oppor­tu­ni­ties for improvement.

One last thing about ecom­merce UX design: 

Ecom­merce UX design is an iter­a­tive process. You’ll nev­er be done with it, and that’s a good thing, because it allows you to fix the things that don’t work and opti­mize those that do. Con­stant exper­i­men­ta­tion, learn­ing, and refin­ing based on user feed­back and data will ensure your online store not only meets, but exceeds user expectations.

OK. Two more.

Tom Fish­burnes always-on-point Mar­ke­toons helped us illus­trate this post. 

If any of this feels like too much, don’t wor­ry. Bet­ter Call Us. We can help.

Santi M

Santiago Melluso