I have the same problem, and I assume it's because advertiser's budgets are going down with the weaker amarican economy
I was pulling about $20 a day, now I'm doing about $2 a day. Clicks are worth a penny or so for me now
LOL, I guess I'm not the only one that is getting penny clicks now !!! Corb, by any chance are you using "Link units" instead of "Ad units" ? the site I'm having a decrease on is using Link units and I'm thinking that might be the problem because I just checked my Adsense and I have 63 clicks for $2.16 on the site with Link units but I had 1 click for $1.53 on another site
I agree, revenue per click is definitely way down. The funny thing is my parked domains with Google ad feeds are seeing revenue much higher. Makes no sense to me...
I have some sites that are doing VERY well right now. It's just this one site that has fallen into the gutter on earnings per click. It's bumming me out.
I think everyone is facing such problem too , In May my earning went down upto 80% . Smart pricing is the main reason which is used by adwords users according to me .But yeas their some good advertiser in tech niche which paid me more than $0.60 per click also .