It depends a lot on the content. If you're targeting a lucrative niche, contextual ads can be effective. But for the majority of (mostly low-quality) content, i

It depends a lot on the content. If you're targeting a lucrative niche, contextual ads can be effective. But for the majority of (mostly low-quality) content, it's hard to find well-matched ads. The study you cited is based on "a rich dataset of millions of advertising transactions completed across multiple websites owned by a large media company". It's probably not that representative.