Google is behind webmasters who purchase sponsored links. What will google do for their own site.. See at the bottom of this page... http://cyber.law.harvard.edu/home/sponsors Its from an edu site Google's link at bottom and that also without no follow
well on that page if it would have been a gambling link instead of G's link then you would have said that its an paid link to increase rankings...
That's a good example of a link that *could* be interpreted as paid. One thing though, the anchor text is Google Inc. If it were keywords instead, I think the page might very well get a closer look.