Making One Service Icon Larger: Mobile App A/B Test

A heatmap with clicks scattered across equal-size icons is the first clue that the priority service gets lost on mobile; visitors reaching its target page through search or long detours, and support requests from people who could not find it, back that up. If the larger icon draws the eye, visitors reach the priority service in fewer steps and finish what they start there. If visitors find the service but drop out partway, the problem is the service flow rather than the icon, so look there first; and set the enlargement so the icon never starts to look like a banner.

Featured service completion rate

Compare completed actions for the featured service per assigned visitor.

Also track

• Icon click-through rate (CTR)Check whether a larger icon receives more clicks.
• Category entry rateMeasure visits to the service's target page.
• Clicks on other servicesMake sure other services are not overshadowed.
• Navigation efficiencyCheck whether visitors reach the target page in fewer steps.

• SizeIncrease one predefined service icon by a fixed amount.
• AppearanceKeep color, position, label and destination unchanged.
• Other servicesDo not change other icons or access paths.
• PlacementA different order or screen position requires a separate test.
• SelectionDo not change the featured service or add another service during the test.

1. 1A lift in icon clicks is not a win on its own. The featured service completion rate should make the call; if clicks rise while completions stay flat, the larger icon may only be drawing curiosity.
2. 2Read clicks on other services and category entries together: if the featured service gains while access to other categories slips, the larger icon is overshadowing them. In that case, revisit the enlargement and whether the icon reads as a banner before you ship.
3. 3This result covers only this service, this enlargement and this mobile layout. Featuring a different service, or changing the icon order or screen position, calls for a separate test.
4. 4A longer run may be needed when no clear gap shows, because completed service actions are rarer than icon clicks. Enter the current featured service completion rate into the sample size calculator to get the sample per variant, divide it by daily visitors per arm to set the run length up front, and do not decide before it is over.