This could be a great success story for well funded start up Outbrain. I think Google may be running ads via their content recommendation system.
Who knows what might happen if Google are testing ads on Outbrain and they like the experience. Eric Schmidt has hinted that acquisitions are back in the air for the search giant.
Outbrain's widget is normally used to place rating stars at the bottom of blog posts. Below these stars the widget will start to make content recommendations. Those recommendations may come from the blog hosting the widget, another blog running the Outbrain widget or a lucky "premium" blog that Outbrain have added to the engine.
It's not quite a traffic exchange but if you don't mind some outbound traffic then you'll benefit from a little inbound traffic in exchange. I like it because it helps this little blog feel part of a larger blogging community.
This year Outbrain started to run ads via these recommendations. Advertisers find blogs that have genuinely said something positive or helpful about a brand or a product and then use the recommendation system to highlight those posts. Keeping it ethical Outbrain discloses those handpicked recommendations as ads.
I'm still testing them on this blog, as they're funky but any pennies generated go to charity (an option Outbrain provides for everyone). That's the source for the screen shot above which seems to show someone highlighting a pro-Chrome post. Could that be Google?
This is a valid alternative to AdSense and hugely more "social media" than the ubiquitous text banners have become. Outbrain's one to keep an eye on.
Update: Eytan Galai, Director of Finance at Outbrain, informs me that the advertiser isn't Google.