What kind of placeholders were they? Also I have suspicions about what you are measuring being 100% correlated with "better user experience." Lack of user drop

What kind of placeholders were they? Also I have suspicions about what you are measuring being 100% correlated with "better user experience." Lack of user drop off CAN indicate a better user experience, but the concept of "click bait" illustrates that you can gain short term increases in attention in ways that both decrease user experience and can contribute to driving away users in the long term. I'm not saying this sort of thing is the same as click bait, but still. I'm sure that in theory, you could put lots of things in those placeholder spots that will increase the number of people that wait for the page to load, but may drive away users in the long term. (e.g. blurry nudes)