Just to add to that, on my main job as a web developer, we had contracted to an SEO company some years ago, and they were constantly in communication with Google. One of our web sites had done something Google didn't like in the past, and Google flagged that and it was killing its position in the search rankings. Google themselves won't tell you much more than that, but the SEO group was able to figure out what it was and get Google to give us a clean pass.

Used to be that way. Just from personal observation, I concur with the poster above that this relationship has broken down and it's worse for everyone.