Good traffic but very low CPC

Hi,

I'm new to Warrior Forum, but I use to keep visit this site long time ago.

I've learned a lots from this forum and I found lots of great resources and it was very helpful.

Now I'm really having a trouble here and not sure if this really can be improve...

I have an average of 5,000-10,000 visitors a day and my Adsense revenue average of $2 a day. I use to make more than that, but it just because I use to have little bit more traffic like 10,000-20,000 visitors a day and making over $10-$30 a day.

Now I don't know why my CPC is very low.

I'm using Wordpress which I place 1 728x90 ads on the header, 300x250 on the side bar and 428x60 bottom of the first post. with two 428x15 link unit ads bottom of the title.

I'm using SEO plugin like Yoast SEO my rank on google result I don't think it is really that bad, people usually find my site from google and I've Facebook fan page with over 15,000 likes which bring me good traffic sometime.

Like today I have post some article with over 1,100 likes+share to facebook.

But I still don't know I only earn $4 from 72 clicks?

Here is my overall ads report

img217.imageshack.us/img217/9711/2012050918h3705.png

And here is for today.

img220.imageshack.us/img220/2742/2012050918h4648.png

I really need some advice on how can I improve this

I did block many URL that suggested to be block on adsense filter too.

Thanks