When in comes to advertising your site, paying for advertising could actually end up hurting you. Google has recently punished anyone who had paid links on their site by knocking them down in Page Rank. In turn the advertiser who thought they were paying for a link on a PR5 now gets a link on a PR2. Of course this doesn’t affect anyone using Google’s advertising system.
There is also Yahoo, but their advertising program is still in a beta and there is no telling when that will even be open to the public. It has been in beta for over a year and I haven’t seen any signs of it coming out of the beta.
You do not need to rely on those two though. Let the giants cancel each other out, go with someone who is for the little guy, go with Adknowledge . Over 50,000 advertisers have used the Adknowledge BidSystem and they are growing every day. If you go with them you can get $50 in FREE PPC Advertising and at prices that are up to 30% cheaper than Google and Yahoo this is definitely a bargain. If you want to advertise your site you want someone who is going to be there for you when you are starting out, $50 free PPC advertising shows that they are looking out for the little guy, as well as the big guy.