Making money from Adsense impressions?

I've read that Adsense shows CPM ads that pay per 1000 impressions but have never received anything from this.

Is anyone here earning anything from impressions or just clicks?
Is it automatic, or is it an option somewhere that you have to opt-in for?
What kind of money can be earnt this way?
Do you get paid on 1000 impressions per ad, ad block or total impressions in your account?

Very curious.

I have a site that appears to be getting these ads. Unfortunately, the traffic on that site is minimal. With the CPM ads I am getting, once in a while I see a penny or two. I suspect the ad(s) that is CPM is having my account credited at something less than 1000 views due to the traffic and frequency I see the pennies without clicks show up.

a few pennies? i was hoping it would be a bit more than that ;)

Glad to hear you can make something through CPM though.

you get paid for impressions if some advertiser has selected your site via adwords

Thanks for clearing that up Olaf.

I wasn't aware you could select to have your ads shown on a specific site with Adwords. I'm going to look into that.

So, if an advertiser hasn't selected your site, all Adsense ads will be PPC? Is that right?

yes

Hmmm, that's got me to wondering. So there is someone out there that is paying me a penny per xxxx impressions to be on my site and their ad is replacing the network ads; some of which can pay me as much as a $1.50? Oh, that is so messed up. Can I in turn block them?

You can block them, and it is good to block them because they don't really earn you any money. Personally I prefer to use other CPM companies in the sites that  don't make much with adsense, because the adsense pays around 0.20$ CPM which is very low....

you exclude them right? but how do you know which domains you need to block.

finding the right CPM partner is very hard, you get only accepted (by good paying publishers) if you have a site with more than 2500 uniques a day

You don't have to block domains. You just block image ads from a certain ad box.

oooh, only the image ads are CPM campaigns? I thought to remember me that I started some CPM based text ad with aswords...