I know CPM pay based on every thousand impressions, so whether or not you get any clicks doesn't matter, but are they a good option to monetize a website? Also, what formats are available for CPM ads? Are they just regular text-ads like in PPC advertising? One more thing: How is the content of CPM ads controlled, (through keywords, contextually, etc)?
CPM ads are mostly banners, and they are not controled by you as far as i know, your ad network set the suitable ads for your account... and yeah you earn alot of cash if you have high traffic website, most of hte people that does CPM is because they users doesn't click so often so they go to the better way to get cash.
Actually, some company do care about click rate on CPM ads. If your click rate on CPM is exceptionally low, then you cpm rate may drop or kick you off the network. Most CPM networks are not contextual; sometimes their ads are really annoying, often containing mostly flashy graphics.
Thanks, guys. As much as I hate those annoying flashy things, especially the ones designed like a windows message that say "Your PC is infected!!" I doubt that most people fall for those, but they're still irritating. Anyway, I was thinking about using a banner at the bottom of my page (my site, by the way is http://master-of-metal.blogspot.com if you're wondering). Any CPM company recommendations?
Use Adbrite. If you have a lot of traffic on your site, such as an active message board, you can make several dollars per day just using their network banner ads.
Never forget the big brother they have the best cpm rate ads and the most advertisers: Google, fastclick, Rightmedia, Doubleclick (now googles) and more...