Never heard of it. The great thing about adbrite is you can do either CPC or pay daily / weekly / etc. on the site of your choosing and get some pretty good estimates as to the CTR's.
I would try looksmart, kanoodle or 7search. They should be cheaper then AdWords. However the quality of traffic may be not so good as with Google.
If adwords is used correctly you can get valuable visitors with low cost, depends on the person who manage the campaign. Wondering what would be the reason!