Google recently announced that they will be including the +1 button into AdSense ads. You can read more in the post, but this has significant impact for advertisers who can now get a ton of social data combined with their campaigns.
From their email to AdSense customers
We previously launched the +1 button on Google search and for publisher sites to make it easier for people to share and discover content across the web. Soon, your users will be able to endorse specific ads and make the ads more likely to appear to their social connections. We believe that these recommendations could help your readers notice ads on your site more, leading to higher returns for you over time.
This is what the ads will look like – very similar to the Facebook “face pile” you see on sites where you have friends that have OAuthed
Its definitely an interesting move to increase engagement within advertising. There have been a ton of startups that have tried to tackle this problem and increase relevancy to readers and users by requesting implicit and explicit feedback from users, but none with the sheer scale of Google. AdSense ads obviously litter the web and are a core source of revenue for many sites so the immediate impact here will be known. It remains to be seen if there is an increase efficacy of the ad for either relevance, click through rate, or even recall but I will be following this closely to see the results.