I'm very confused what CPM rates to charge for banner advertising. I see a lot of sites are averaging about $5 CPM. On the other hand, most big IT sites (Devshed, The Register, The Inquirer, etc) are charging $10 to $50 CPM. Am I out of line asking for $5 CPM to $16 CPM depending upon the ad position, size, and how targeted it is? Is $16 CPM out of line for a forum regardless of features such as forum-targeting, frequency capping, geotargeting, etc.?

I think 5 - $15 CPM is too high for a normal small biz to ads on heavy traffic website.
So for as Google Adsense is concerend I get < $0.5 CPM ads most of the times. So I think u asking for $5 is pretty huge.

Well the first thing to remember is AdSense is text based, so that lowers the equivalent CPM that AdWords advertisers are paying to be on your site. In addition, DaniWeb generates a LOT more than $0.50 CPM via AdSense, although it violates their TOS to say exactly how much. In addition, I am targeting large companies to buy DaniWeb advertising

I could see now you have started using LakeQuincy ads in your Microsoft .NET related pages. How has been your earnings lately? I used to get high CPM rates for the ads shown. It looks like they have reduced it now. How has been yours?