adcenter content traffic

i was wondering if anyone knew how to get traffic on msns content network and how much cpc your paying? seems like they dont give much traffic or im using the wrong keywords. Anyone having success with this?

 

adcenter is for only Advertisers or Publishers can also participate?

 

I would like to know this as well, seems like you either need to bid a ridiculous amount or you need to use very plain high traffic keywords.