I haven't used them, and am not sure what type of information you are looking for. Out of curiosity, I did a quick search.
Going to the Adify website displays the content for "Cox Digital Solutions". The scrolling newsbar there has the message: "Cox Cross Media and Adify have merged to create Cox Digital Solutions". This apparently occured in January 2011.
The Cox Digital Solutions website can be directly directly accessed.
There's a wikipedia article with enough relevant information to start digging elsewhere
It appears to be a major ad network. There are some media mentions in major Advertising trades, as well as major national newspapers.
Seems like whatever you might be looking for is out there, and can be found with not much difficulty. I found this in about 5 minutes, with no effort.