If you're ever struggling to think of a niche and market to enter, sign up for the free newsletter at http://www.nicheaday.com/. They give you an email everyday which contains a single niche market, the monthly traffic it gets and the current high PPC bid for that particular niche, and also a spreadsheet file (Excel/Open Office compatible) attached to each email containing up to the Top 1000 keywords for that niche keyword. Their keyword data comes from the largest keyword database with data from over 180 search engines. Each spreadsheet includes the keyword and its search demand for the entire last year, sorted from highest demand to lowest. Your preliminary keyword research is then done and you can begin to instantly look for sub-niches to expose. (Powered by NicheBOT 2 - http://www.nichebot.com) It's a great site which I've used multiple times to come up with an idea on which niche to enter and I highly recommend it.