The use of keywords and search engine results is vital to the success of your AdSense sites, and for me the best way to identify profitable keywords and phrases is the biggest challenge in my internet business. I would rather spend hours cleaning out the fish tank than do my keyword research: however, when you get it right there are huge dividends that will translate into cash for you. Imagine you have a website selling fish food. If you chase those keywords it will cost you a fortune on your Google Adwords budget and there will be millions of other web pages carrying the same phrases. But dig a little deeper into the niche and you will find interested aquarium owners looking for help with their fish diet. Did you know, for example, that fish food is also fed to snails in captivity? So you can target owners of more off-beat pets and supply everything they need for their non furry friends. Think how much easier it would be to  build up a presence in the niche of owners of apple snails, than fish keepers in general.