Recent AB tests we’ve done suggest that many ecommerce sites could see an increase in mobile conversion rate by adding a “bar” of navigation links at the top of their mobile homepage, instead of relying solely on the hamburger menu.

We’re calling this a “Top Nav Link Bar”, or just “Link Bar”.

The Link Bar is an alternative to the much hated “Hamburger Menu”, which hides links behind the famous 3 bars (the hamburger). It’s hated enough to where simply Googling “hamburger menu” returns anti-hamburger menu articles in the top 5 results!

In this article, we’ll discuss the Link Bar concept via two AB test case studies where we saw increases in visits to product pages and purchase conversion rate.

Finally, we’ll also show a set of design examples from popular ecommerce sites that implement a Link Bar concept in different ways.

Our hypothesis is that the Link Bar lets shoppers get to the product pages faster by exposing product and category page links normally hidden behind the hamburger menu. One less click is required and the links are more prominent, so it increases the chances of users proceeding “down funnel” and seeing products.

Let’s get to the two case studies.

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Mobile navigation Link Bar increase orders by 5% for an apparel store with 1000 products

First we have an apparel client that has over 1000 products across 9 categories (and multiple subcategories on their site).

So, pretty stereotypical ecommerce company.

What did the mobile homepage look like?

Since we anonymize clients , let’s use the mobile homepage of a well known brand that had a similar layout: Urban Outfitters.





Key characteristics of this mobile homepage (that were true of our client’s mobile homepage):

Large image based full bleed photos that change depending on the current marketing campaign (about once a month)

Main navigation hidden inside the hamburger menu

If you scroll down far enough there are eventually links to categories

Here’s what we tested:

In the variation, we simply added the Link Bar, to the homepage only. There were 9 categories.

Note we didn’t replace the hamburger menu, it’s still there and still is the most thorough way to navigate the different product categories.

But it’s no longer the easiest way — the Link Bar is.

The Link Bar was left-right scrollable and had arrows to help indicate that.

Here are the results.

First, completed orders. After 28 days, we saw a 5% increase with 93% statistical significance:

Note Optimizely’s stat engine uses a more rigorous “two-tailed” statistical significance calculation, which does not give this any significance, but a traditional p-value calculation shows this:

So this is not a “runaway winner” by any means. The industry convention is to declare a winner if it reaches 95% statistical significance or higher when the test reaches your pre-determined number of visitors.

But that is, in the end, a “convention”.

With over 80,000 visitors, 2,300 conversion events per variation, and having run for exactly 4 weeks with the variation leading basically for the entire test, we felt the conclusion was “this is likely a winner and is more likely to perform better by 2% – 5% over longer periods.”

But that’s just one metric (albeit an important one). The story gets more interesting if you look at additional metrics.

Only the exposed listing pages showed an increase in pageviews

Pageviews of the category pages showed clear increases by 10% – 12% (with 99%+ significance), validating one of our critical hypotheses that the Link Bar would send more users “down funnel”.

For example here is the first category link on the left of the quick Link Bar we added (e.g. the “TOPS” link in the “B” mockup above):

The other two category pages showed similar results.

But those pageview increases were only seen for the exposed category links:

What about the links that were “hidden behind the scroll” in other words, you needed to use either the arrow, or scroll to the right to reveal them?

They showed no change in pageviews:

This was consistent for all the category page links that were hidden behind the scroll.

This confirms the original hypothesis of this test: Revealing links to product and category pages will increase the amount of customers reaching them.

Certainly if category pages that were just to the right in our Link Bar didn’t see an increase in pageviews, then hiding all links behind the hamburger menu does the site no favors in terms of getting shoppers to the products.

Takeaways for your mobile site:

Test putting links to your most popular product categories at the top of your mobile homepage.

Try making the bar scrollable and see if you can reproduce this result in your store.

Do you see indications of an increase in completed orders like we did? Maybe your store shows a far more definitive increase in conversion rate than the slight possible lift we saw above.

Case Study 2: Health food brand sees 29% increase with a navigate Link Bar on the homepage

Next we have a very different ecommerce brand, in the health food space with 3 product flavors.

Again, the homepage had copy and images and links but you had to scroll down the page to get links to the 3 PDPs.

So we added the navigation Link Bar just like before:

The variation in this case had links directly to the PDPs of the 3 different flavors (which each had their own PDPs).

After 14 days, we saw a 29% increase in orders with 98% significance.

Traffic to this site was lower, however, so the test got only 139 vs. 107 conversions per variation. This is low. The difference is only about 30 orders, so again we have to put a qualifier that the variation “likely” performed better.

However there was no indication that it would perform worse than not having the links.

Link Bars can help expose customers to new products

In this case, of the 3 flavors, the second and third flavor saw a large increase in PDP pageviews (Chocolate and Strawberry in the mockup above): +25% more visits, and 77% with 99.9% stat significance and over 600 conversions per variation.

But, the most popular flavor did not see much of an increase.

Why?

In this case the site was known for their most popular flavor. Historically that was the only flavor for when the brand first launched. Referral links disproportionately went there, blog links disproportionately link to that flavor, and the homepage imagery and copy mostly talked about that flavor

So in this case the Link Bar served to expose more customers to the rest of the company’s offerings.

This is a nice additional benefit of Link Bars. Note that those alternative flavors were inside the hamburger menu also, but as we saw in the first case study, having them exposed on the page (via the Link Bar) showed a definitive increase in visitors to those PDPs.

Conclusions and how to apply this to your own mobile ecommerce site

Taken together both of these tests, on two very different ecommerce stores (1000 products vs. 3 products), suggest a similar theme:

Make it as easy as possible for mobile shoppers to get to your product offerings.

If you have hundreds or thousands of products, put links as close to above the fold as possible to your most popular categories.

In the first example above, a natural iteration of the test (that has not yet been tested) would be to stack the links instead of having them be in one scrollable row.

This will give shoppers an even better overview of exactly what the store offers.

This should send even more visitors “down funnel” and perhaps give the test a more definitive win over the baseline.

If you have only a few products, create top nav links to the product detail pages.

Finally, as always, you should test this yourself. Don’t assume these results will apply to your store.

Both of the AB tests above saw definitive increases in visits to the category or product detail pages, but the increases in order rate weren’t “runaway” winners, which we define as 99%+ significance with hundreds or thousands of conversion events for each variation.

That’s okay though, as we’ve written about before, not all ecommerce stores have the luxury of that much data . That doesn’t mean you throw up your hands and not test anything nor does it mean you should just use the old fashioned method of “debate designs in a room, loudest voice wins, and implement it outright”.

That’s even more dangerous.

Aside: We once had an in house designer form a client ask if they could implement a hamburger menu on desktop because it “looked sleek”. (Facepalm)

This is why testing is important, even if you don’t get picture perfect increases in conversion rate (99% significance, and thousands of conversions over many weeks).

What about desktop? Why is this mobile only?

The reason this isn’t relevant on desktop is because almost all ecommerce sites have exposed links to all categories (and often dropdowns to subcategories, aka a “mega menu”). So this is by definition almost always already implemented on desktop.

It’s just that the space constraints of mobile result in the hamburger menu.

Hopefully this article and this data we shared helps you start to think outside of needing to collapse everything behind the hamburger menu and starts opening up other possibilities.

On that note, our variations aren’t the only way to go about this. Here are several more examples of alternatives to the hamburger menu from different ecommerce mobile sites.

Ecommerce mobile homepage examples

Who is doing this well already?

Here are some other brands that have clear links at the top of the mobile homepage, getting rid of the complete dependence on the hamburger menu:

Gap.com

Gap has a lot of products and categories. They have clear links to the main categories at the top of their mobile homepage:





The use of photos is a nice touch and could possibly increase engagement with the links and clarity for certain stores.

Note the links are not sticky upon scroll, whereas the links to Gap Incs other brands at the top of the page are. Interesting.

Abercrombie

Also in the apparel world, Abercrombie chooses to simply split by Men and Women. This is worth testing versus a deeper category split like Gaps above:





Lowe’s

For search heavy stores, Lowes.com has a great example of both featuring search and using a suggested area to basically push some category links. We hadn’t been to Lowes.com on this device before so these were likely just categories they wanted to promote (versus a personalized list based on past visits).





Finally, here’s a more bold homepage concept by Cos Clothing, who doesn’t need a thin strip of suggested categories but rather just dedicates the bulk of the homepage to sending shoppers to the right categories.

(Note by the time we published this article the Cosclothing homepage had changed to include a promotion at the top instead of full bleed photos linking to women and men’s departments.)

They have full bleed images for women and men followed by clear links.

We would love to test something this bold with one of our clients.

Final Aside: the homepage is often sacred ground for ecommerce organizations. People fight and negotiate over screen real estate there. So even we, as a third party optimization agency, often have severe restrictions on testing the homepage, much less radically redesigning it. Much thanks to the two clients who let us run the tests featured above.