What niche are your sites based on? You might be better off promoting affiliate products. In a niche that pays peanuts from adsense, I'm guessing that eBay or Amazon affiliate programs may perform better.
Getting $.02 a click at times is pretty normal even on sites that normally average $1.00 a click. Averaging $.02 a click over 400 clicks is terrible! I've got a few poor paying sites but nothing that bad. I think the previous posters idea of a click bomb seems likely.
In the last week my clicks have all been ranging from 4 to 7 cents. A couple of months ago they were worth about five times as much. Same site, same ads. Suffice to say I'm not impressed. At all.
It's little. I think quality wins number...Check your paymaent for keywords...and check where your traffic come from. It plays a great role...
That is super low. I average about 60 cents per click. Change your niche and you will see better results.
Just maintain that kind of daily earnings from adsense and you can quite an amount after a month. Although it is better to aim for more, like 10 to 20 dollars a day from Adsense. So much the better right?