[hugey010]

I believe that it not only increases engagement, but also increases likelihood to click ads and buy things. People seem to like to shop as a distraction / coping mechanism.

I have no evidence of this but I have thought quite a bit about why social networks angering push content the way they do.

[nowherebeen]

Yes, it's correlated. YouTube ads are a great example. The more you use the platform, the more likely you will see an ad. At the end of the day, these companies maximizes profits for shareholders. Users are a means to do so. Advertisers are the true customers.