If you want to boost your Adsense earnings then displaying High paying keywords is what you need. There are a lot of high paying Adsense keywords which you push earnings up to the next level. One of the high paying keywords that I found is Home Equity Loan, though range differs everyday its paying rates is much higher than any other keywords that Adsense will display.
So what is Home Equity Loan? as defined by wikipedia, it is a type of loan in which the borrower uses the equity in their home as collateral. These loans are sometimes useful to help finance major home repairs, medical bills or college education. A home equity loan creates a lien against the borrower’s house, and reduces actual home equity
Using this keywords would translate better Adsense earnings compare to ordinary keywords but of course it is an advantage for you if you are generating a lot of your traffic from the US, Canada or Europe. Home Equity Loan is usually done in the said country above the more clicks your visitor generates the more earnings you will get.
Among other keywords are related to Loans, like personal loan, student loan consolation, payday loan etc. Target this keywords now and see the effect to your Adsense earnings. You can optimize this keywords for better search engine placement and for better conversion rate as well.