I use gmail for my personal email, and Google Apps Enterprise for my hellofax email. So, sometimes I can see UI tests in action.
Google Apps Enterprise
Notice on the Google Apps Enterprise version, the ” << Back to inbox ” link looks like how the ad looks in the free gmail.
Free version of Gmail
Now, look at the free version of gmail. They got rid of the “<< Back to inbox” text and replaced it with a backward arrow. I’m so used to looking for a blue text link, that I feel compelled to click on the ad instead. I’m completely blind to a button with black styling. Plus, blue is really compelling to click on (Bing blue is apparently worth $80 million). Now, the “<< Back to inbox” blue doesn’t compete with the advertisement’s blue.
Is Google Intentionally Optimizing for Clicks?
I’m not sure if gmail optimizes the UI for ad clicks. Intentional or not, I can almost guarantee that a statistically significant number of users now click on the advertisement by accident. At least, people finally notice it again, after getting used to ignoring it. Over time, people get blind to ad placements. One approach is to simply move around the ads. What’s brilliant about Google’s approach is that they just changed the color & made it into button, without moving the UI at all. I’m sure this had a significant impact on the revenue of this ad placement.