The Core

The top 10

http://www.federatedmedia.net/blog/2011/04/tuesday-signal-googles-biggest-advertisers/

I wonder what those ebay numbers would be like if they counted affiliate advertising?

I would have put money on Groupon being in there at first, then I realised this was a list of foolish advertisers, not good advertisers.

Groupon use retargeting so well you think they are everywhere on Google but they are not.

Mind you, I would still expect them to be there, but maybe this is just US spend and Groupon are creating demand in new markets where they now have supply, clever stuff indeed.