Well, some good news, Google have finally released content bidding within adwords,  we've been asking for it for years - a hot topic 2 years ago at SES.

You can now specify bid amounts for content ad placment at 'ad group' level:

Prior to this change a single keyword bid was applied to ads on both search and content pages. The lack of a separate bidding element restricts campaigns, however now choosing bid amounts gives control over content ads & a better understanding of content placement, definitely a move in the right direction.

Googles comments:

"If you find that you receive better business leads or a higher ROI from ads on content sites than on search sites (or vice versa), you can now bid more for one kind of site and less for the other. Content bids let you set the prices that are best for your own business. "