Techmeme probably pioneered this idea, but somehow it has not spread to other websites. The tech news aggregator displays editorial posts on the left column, and on the sidebar they have a section titled “Techmeme Sponsor Posts.”
On that section posts from the blog of the advertisers get highlighted, sending qualified traffic their way. Considering that the monthly cost for one spot is $5000 and that they have around 6 sponsors at any given time, it must be working well.