My sales reveal clearly when what I have termed the "old" and "new" results are running - because the "new" results don't produce any sales...and that's because my sites (health sites) aren't directly featured.
What does appear in the results are what I'd term feeder sites, in other words, satellite or peripheral sites which link into the main sales sites. All of them are substantive sites with useful content, so it's not an issue of substance. This seems to be much more about the identification by Google of networks of sites interlinked in a way that allows them to spot self-promotion. There's also something going on about links, which seems to amount to a downgrading of the value of anchor text on links into a site. The same may be true of onpage factors.
For example, the search term "causes of xx", where xx is a medical condition, produces inexplicably similar results to "treatment of xx" and "cures for xx" - or indeed, "xx treatment" and "xx cure". This is a very new development, and the results presented seem rather generic, not specific to a cure or treatment of cause for condition xx; more a sort of general information resource. I suspect that could be to do with quality and authority signals being rated more important right now than content and link factors like anchor text. So there may be some kind of evolution or trial going on, but once again the results don't seem to offer the searcher exactly what the search terms imply.