I agree with Play_Bach. Most of my small to medium clients are ranking well but they do not advertise on Google now and they never have. It takes just a small amount of research to disprove any connection like that.
There are a multitude of ranking factors and we don't know the full recipe for how they combine. This algorithm change is, so far, not having all that big an impact, even if it is causing concern for some.
We are not being lied to when some new change is publicized. At this point we even get a monthly article for all the changes that Google launched in the past month - and so far, it's a pretty big list for one month's work. We just don't get an exact recipe book, and it's become so complex that a true reverse engineering isn't likely.