McMohan - 6:01 am on Dec 17, 2011 (gmt 0)

Its not as much a question of whether it is a paid listing or not, as much it is about the editorial value, IMHO. Why Google frowns on paid listings is because very often editorial integrity is pushed through the window when there is money involved, and you will end up with a Payday Loan link on a Health site. If a site/directory has established its editorial integrity long enough and Google recognizes it for that, Google won't have any issues if its a paid listing, IMO.