[valuearb]

Where is the data on results? I looked at an AirBnB “experiment”, they moved an action button above the fold (duh). But no details on how much more effective the move was.

I am all for A/B testing, but the devil is in the details. You can get more users tapping the purchase by moving the purchase button where users are more prone to accidentally tap the purchase button. That doesn’t mean you get more purchases, or that the move was a positive change.

[gwern]

I don't think they have results. It looks like they are regularly scraping sites and looking for diffs across users. So you can say what the test was, how long it ran for roughly, and whether they kept or rejected it, but you have no way of knowing what the quantitative results are (aside from whatever inferences you can make from estimating the tested _n_ and then assuming they are using an efficient testing procedure with optional stopping / bandits plus the final choice to infer upper/lower bounds on the effect size).