I didn’t know about this new features. Thanks for letting us know dan

Just a heads up, Channel Makers released a video on this topic that probably will give you more insight into how this new program works. But to give you the low down, you probably need to get 5000 impressions withing 2 weeks for the Test and Compare feature to work. So in the case of this video, it's highly unlikely that you will get any results. So to answer the question about how long the test takes, if you can get 5000 impressions in 10 minutes, then the test will take 10 minutes. If it takes you 10 days to get that amount of impressions, then the test will take 10 days. If you can't get 5000 impressions within the test period of 2 weeks, you will get no results and the first thumbnail will be chosen. Hope this helps.