Increase your adsense earning .I researched on Google Adsense earning of many publishers have falling down. They say's that earlier they were earning about $3 to $5 / day but now they are earning 00.01 cents to 00.50 cents earning every days. The revenue dependes on the type of google content and keywords you have on your site. If there is heavy competition on particular keyword .There is more possibility to earn more on those keyword or content site. Here are some heavy revenue keywords .

1. loans
2. personal loans
3. car loans
4. payday loans
5. mortgage loans
6. federal loan
7. student loans
8. direct loans
9. debt loans
10. finance loans
11. credit loans

The search volume of these keywords is very much high .Therefore, to get traffic on search engine like Google ,Yahoo .You need to have heavy traffic with google page rank for this.In this way we need keyword whose search volume it low but the keyword competition to advertise on adsense is high.
Here are some of the keywords whose competition is high in adsense but the search volume it low .The small sites can you these site to get top page ranks as well.

1. auto loans
2. bank loans
3. car loans
4. cash loans
5. cheap loans
6. commercial loans
7. credit loans
8. debt loans
9. direct loans
11. finance loans