Bottom line: they probably sell more ads with those changes in place.
Why Google has 200m reasons to put engineers over designers
"About six or seven years ago, Google launched ads on Gmail," Cobley explained. "In our search we have ads on the side, little blue links that go to other websites: we had the same thing on gmail. But we recognised that the shades of blue in those two different products were slightly different when they linked to ads.
"In the world of the hippo, you ask the chief designer or the marketing director to pick a blue and that's the solution. In the world of data you can run experiments to find the right answer.
"We ran '1%' experiments, showing 1% of users one blue, and another experiment showing 1% another blue. And actually, to make sure we covered all our bases, we ran forty other experiments showing all the shades of blue you could possibly imagine.
"And we saw which shades of blue people liked the most, demonstrated by how much they clicked on them. As a result we learned that a slightly purpler shade of blue was more conducive to clicking than a slightly greener shade of blue, and gee whizz, we made a decision.
"But the implications of that for us, given the scale of our business, was that we made an extra $200m a year in ad revenue."