Stumbled upon an untouched niche last night. The potential customers generally are well educated and have a good amount of disposable income, and are always searching for more/new info. And best of all - they seem pretty damn gullible to me. It's the unexplained mysteries/cryptozoology/ghost hunters etc. go to this site and take a look around http://www.unexplained-mysteries.com/ I've done no keyword research or anything, because I'm too busy to do this myself (why do you think I'm giving it away!) but have a look at the activity in the above forum, theres gotta be some $$$ in something like a small ebook on "how to photograph spirits and ghosts using a simple digital camera" or "Leaked Bigfoot Study, the government doesn't want you to see"