Last year we saw a great use of "contextual" banners, updating the content in real-time so they were always updated to the information that the page containing the banner was displaying. Yesterday, while i was voting FIAP awards i found out this clever banner campaign done by the always clever people at Almap BBDO in Brazil.
The thing itself goes like this: displaying a recipe post in one of the most respected advertising blogs in Brazil (Brainstorm9) and next to it displaying the ad, that reads something like "this is the first time you see a post like this in Brainstorm. And this is also the first time you can see a sedane like this" (a new VW car)
Probably there are more executions in different sites covering different topics, so it appears to me as a clever way of buying online spaces to promote a new campaign.