Amazon's Loaded Hamburger Menu Beats Its Older Dropdown Version In This A/B Test

One of the first visible changes in this experiment was the shift of the broad "Department" menu from the navigation (A), towards the upper left into a "Hamburger" menu. Yes, this also means that the "Department" label disappeared and was replaced with an icon (B).

Interestingly, the experiment wasn't a simple menu shift as after clicking the hamburger icon, users would see a very strong call to sign-in as the first option. This of course wasn't visible in the control. I would guess that encourgaing users to signin, allows Amazon to surface more relevant products and makes for an overall better experience.

The B variation menu was longer and contained more options. As a result of this a scrollbar was also added.

Perhaps subtle, but you might notice that the B variation menu has more padding between menu option. More padding of course is known to make selections to be performed more easily - especially when using fingers.

Another difference between the control (A) and the variation (B) that ended up winning, was that most options contained a second level. Clicking on "Echo & Alexa" for example would bring up another level of options specific to that selection. 

And last but not least, the B variant menu also took up the full 100% height of the screen.