SEO is a numbers game. If you like things that run on auto-pilot once they are setup, then this may be the method for you. If you get to the top of Google in your niche for a keyword that gets a good amount of traffic, money is guaranteed. In the worst case, you can always sell Google AdSense space which gives you commissions each time a user clicks a Google advert. Better forms of monetization include Amazon Affiliate products, eBay, and promoting member sites in your niche (if they exist).