This is the cycle of a lot of ad-driven businesses. They start out sleek and quick to load because they’re ad-free. They grow insanely fast and burn runway. Then they begin loading the site down with ads to monetize the users. This leads to a gradual exodus and eventual death (or death in the star-like sense of eternal irrelevance).

It seems to be an unstable equilibrium. If you want to stay on top in terms of users and actually make money you’ve got to have a lean and highly optimized site with non-intrusive ads. On the other hand, if you give in to the temptation to take any ad who wants you then you doom the site in exchange for a short term profit.