Do other people have an interest in your niche?

If you choose a topic, you may think that you know at least a few people who are interested in this topic. But do you really know how many people are searching for it in Google and the other search engines? Well there is an easy way to find out. Head on over to the free keyword tool at Wordtracker and do a search for your topic.
So now it's your turn to go through each of your topics and see if they are searched by people or not.