if u not using your domain you can park it in some parking sites which they pay for you if you get visitors look in domain section lot of nice and real threads about parking is discussed by domainers
Parked domains are like the ones in my signature. Basically it's just a company that has slapped together a few templates and who use the Google/Yahoo! AdSense feed. Not everyone can do this because it requires a certain amount of traffic per month. Last time I enquired it was something like 50k. Parking domains can be lucrative but to be honest, most domains don't receive enough natural traffic to make enough money. KP
ND bans you and gives a slap one of my domain got lot of invalid clicks and i banned once even i not advertised that name