That's not unusual. It happens to me most of the time. I also asked the same question on another forum and they told me that it's a payment per 1000 impressions.
From what I experienced, it's $0.01 per 400 impressions... Since I got 2 cents after 900 impressions...
I think the pay per impression varies. Sometimes I notice that I have 1 cent from 20 impressions, then increase to 4 cents with more page views. I think if the payment is $1 per 1,000 impressions, then Google will pay 1 cent for 10 impressions. Just hope that you get those high paying picture ads.
0 clicks with .01 earnings than getting 1 click with .01 earning. - i usually get this with my celebrity niche
I just got 7 cents for 400 impressions with 0 clicks.... Honestly, I'm now confused on how this works...
The past few days i've been earning $0.40 - $0.50 cents with 0 clicks. My impressions are not even that high either!