Gmail has never given me decent adverts. Google ads are usually better. E.g. the ad on the top of CFC right now is pretty good... It's an ad for cheap overseas money transfer, which is useful to me because I send a lot of money to relatives in Guyana and the USA.
I'm still skeptical. If I want to spend money on something, I'm going to Google it and research the best/cheapest option, I don't see how ads on cfc are going to have any impact on my choice.