I highly doubt it, but there is a lot of evidence that shows sites do actually rank better for keywords when having an adwords campaign for them. I've experienced this first hand for a number of different websites, as have my customers, and I've read a lot of supporting evidence too
One of my directories shows up on page 2 of Google for a competitive search term, so if I buy links for all the sites that are above mine.... The sites will get penalized and I get top spot??? It’s a Joke! If Google thinks a link is paid then why not just ignore the link!!! A friend asked me to do some changes on one of his sites; he has a page with loads of links to his favourite sites. When asked why he didn’t use no-follow he really didn’t have a clue what I was talking about, if Google jumps to the conclusion that a followed link is a paid link then that will be the beginning of the end for Google.
So if I have 500 high PR links google will just ignore them? why did we both end up with penalized directories then?