Simple answer: Yes Longer answer: You have to do the research and find out what keywords pay. This takes time. The people who make a lot of money with adsense are the ones who have either accidently fallen into good paying NICHE keywords, or the ones that have sat down and done the research to see what pays. Keep in mind, keywords that pay well change just like clothing styles. Keywords follow or are a precursor to the trends. I hope that helps.