I’ve had great success with bulk uploads to Google Base / Froogle. Takes some serious effort, but good rankings are possible. Feel free to send me a portion of you GB feed, and I’ll see if I can help out. Alternatively, ChannelAdvisor, Marketworks, Performics, Mercent, Marchex, Red Zone Global, Merchant Advantage, Andale, ChannelIntelligence, etc. have solutions that might be able to help you.

Long term, I think they should go for a CPA based monetization model and take a very small cut of the transaction. They are already testing out CPA based ads and everyone realizes that CPA based advertising is extremely attractive.

Froogle/GB will not have the problems that the established shopping comparison engines (which use a ppc based model) have in implementing something like this. From my recent Pronto piece for SearchDay, one sr. exec at a shopping comparison engine explained:
“No doubt that a pure CPA system is easier for merchants to administer, but there are big drawbacks for the market-maker in terms more complicated merchant integration which could slowdown adoption and hinder comprehensiveness of coverage. Also, because the CPA information typically lags and isn’t “real-time” (i.e. needs to be consolidated offline and take into account returns and such), it makes it harder for the market-maker to manage/optimize bids effectively upstream in the keyword markets, hampering traffic acquisition efforts.”

And then you have Google Checkout – which if adopted along with Google Analytics – completes the circle for an ecommerce transaction.

Google has said it wants to provide a better solution for its merchants and a “more integrated shopping experience on Google.com.” Well, if they have a way to monetize the transaction – a CPA based model where they could take a small cut, Google Checkout where they get a small cut, etc. – there’s more incentive to push the Froogle/GB listings to the top of the Google.com results.