One of the techniques you can use to examine what people are getting up to on Google's Content Network is to use Gmail. Gmail infamously scans your email, picks out keyword topics and places ads accordingly. You can actually access this data by using this link
https://mail.google.com/mail/?ui=1&view=rl&rlk=[keywords]so, for example, to see Content Network matches to the keyphrase [Matt Cutts] use this link https://mail.google.com/mail/?ui=1&view=rl&rlk=matt%20cutts. You need to be logged into Gmail. Google also gives us some insight to the system.
Your results will differ from mine. You'll see in the image above that I've got UK ads - and that's because I'm at home in the UK.
So, is Google really bidding on [Matt Cutts]? Heh. Nah. This is more likely to be a content broadmatch. Matt Cutts' name gets mentioned on so many SEM blogs that Google's systems have noticed and made the connection.
The system is actually working; if I'm emailing someone about Matt Cutts then I'm likely to be writing about something Matt's blogged about and Google's quite right to be trying to sell me search engine marketing.