You can earn above average rates of return because peer-to-peer lending eliminates the bank function. That means that you participate in nearly the entire interest rate being paid by the borrower, rather than the less than 1% that you will typically earn on certificates of deposit. And you can reduce your risk by investing in slices of hundreds of different loans.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.