Start a small business. Being passionate usually translates to a superior product and better service, which is especially sought after in the age of the anonymous, 1-minute online review. Worried that there isn’t a market for your interests? The fact is that though you may not personally know many people who want what you have to offer, thanks to the internet, there’s a huge market for niche-products (pigeon diapers, chainmail wedding dresses, you name it)… and you might just end up being a trend-setter. To create an online store, you can either make your own website or, if don’t want to self-host, you can sell on eBay or a similar site.
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.