Like most cpm networks lately, adbrite have cpm everything from 1 cent to 50 cents. It depends on type of your site and interest of advertisers in to your site. There is no harm if you try out for a week or two and then you can decide.
Dont expect alot from adbrite as the CPM is very low .. all the products are the same when it came to Cost per 1000 impressions .
don't expect anything more than a few cents per 1000 impressions. how many cents? that would depend on your niche and geo-location of your users.