I might be wrong but from what I gather the yellow pages, thompson local and a bunch of other directory sites sell links. After registering as a business on their sites i got a bunch of phone calls saying If I pay their yearly fee I will also get a backlink to my site helping me in google etc etc. I told them I wasnt interested.

What I dont understand though is how are they not penalised for this? they dont give a backlink under the free version but paid they give you a backlink..

one rule for some another rule for others.