I've really been enjoying Byrne Hobart's newsletter lately. Particularly, this passage:
Even on the consumer side, we engage in a sort of individualized branch of a collective haggling process any time we consume content that is monetized with ads, because we're basically engaged in a continuous debate over exactly how much commercial distraction we're willing to tolerate for a given amount of entertainment.1 Meanwhile, platforms are haggling in the other direction. On a like-for-like basis, ad load almost always goes up, though aggregate ad load growth is throttled because the most shameless sites die off. The reason they can raise the frequency of ads over time is that as they scale, it's easier to find something to keep users engaged, and also that the more they scale, the better-targeted the ads can be.