Hi,
Everybody has a knowledge to share.
Besides sharing your knowledge via forums or blogs, you can write an E-Book about it. Example- How to lose weight in 10 days or less.. How to make $100 a day without spending a dime
How to better understand women (You got your first customer right here)
(1) Why an E-Book- creating your own E-Book is much cheaper than a hard cover book, all you need is a PDF writer and an E-Book cover generator
(2) Content- This is the most important factor when creating an E-book.