I think this is a case where Facebook will do poorly. I'm not sure if there are studies done on this, but it does feel nicer when I get a preroll ad or something unobtrusive on YouTube (and of course no ads on Netflix) when compared to the midroll ads on traditional tv or on certain YouTube videos (it's so rare for me though that I thought I had accidentally clicked a different video when a mid roll ad appeared on my phone). Doing 'ad breaks' seems like it is a worse way to handle advertisement, because a user can just go to a different tab and wait, and easily rewind if they accidentally miss some content unlike on traditional tv where you can't just rewind and the incentive to change the channel is less because you can't switch to something like Hacker News on the tv and read a quick article or couple comments during the ads.