You can use your computer for selling things such as your services or second hand items on eBay, but there are more ways that you can earn a living from your PC.
In recent years there has been an explosion of websites that use content generated by ordinary people to fuel their success. Usually user generated content doesn’t deliver any money to the users, but that's not always the case.
Affiliate marketing is also an easy way to make money even if it’s not megabucks. All you do is put links on your site to various services and products and should one of your readers click on the link and buy you’ll get a kickback for sending the business to the site. Lots of big companies like Apple and Amazon offer affiliate schemes. Services such as Skimlinks provide a similar service but take the hassle out of setting up a lot of different accounts.
If you have a popular blog or website then running adverts can also be a legitimate way of making some cash on the side. You’ll need quite a hefty number of readers to really make good money, but it’s incredibly easy to do if you can build the right audience and get them clicking on your ads.
Of course, there are some less safe ways to make money online such as by playing poker against real people all over the world, but unless you’re a confident player perhaps it would be best to leave this sort of thing to the experts.
How much you make is, of course, limited by how much time you are willing to invest, how hard you can work and in some cases how talented you are at a particular task. If you're not the best photographer then making cash from selling pictures is going to be a tough ask. However, there are ways to have your PC help you to make money through avenues that previously weren't open and even if they don’t make you enough cash to retire early they can be a useful little addition to your monthly income.