Popular YouTube videos can bring in tens of thousands of dollars in a very short amount of time if they go viral. These videos might be shot with a phone camera and may not even be a minute long, but they provide entertainment value that has rarely been seen elsewhere. Anyone with a YouTube account can sign up for the YouTube Partner Network allowing them to monetize videos.
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.