Recently installed a cache plugin, it came with a ridiculously high level of adverts.

I don't prescribe to advertising as necessary (you're putting billboards on my tool, without my permission), but if the advertising is done well, its, to me a sign of a good developer who understands user experience and user interfaces. Most WP advertising on the dashboard just highlights a lack of thought.

I installed it the cache plugin and ended up with cache enabler, which has 1 admin notice but a very small one about a paid feature.