huh? Google offer this service, where you send searches to them and get paid if people click on the paid links.
if your talking about ppc programs google adwords is the best.. you can also try adbrite for cheaper ppc
Nope, that's only true if you approach it with minimal knowledge and a small budget. We quite happily make a lot of money from Adwords
Just like what the rest have said.. there are other alternatives.. you can create an account in adwords and pay cheaper.. It's not necessary to look for a company for ppc, you yourself can do it.