Clearly, there's a lot of demand on Amazon, and if any product is going to sell, it's going to sell well on Amazon. But the goal here is to source the right products that will easily sell at the world's largest online retailer. Generally, products between $10 and $50 sell very well here. Just be sure to do the right market research before jumping on this bandwagon.
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.