Of course you probably already know the answer to this but, you will not find anything comparable to Google and being when trying to get traffic. We have set up million-dollar campaigns driving a large sum of traffic and for us any time spent on anything other than search engine PPC from Google and being tend to not produce a good ROI when taking in consideration the time to manage each.
I would only suggest Facebook PPC. If you have the funds to invest in building up a fan base for your page at least 100 or so before driving traffic directly to your offer. Typically it will cost you around a dollar 50 for each fan , but you can with the proper skills optimize down to around $.45 for each.
