1. Google Adsense. This is just one example of the many ways you can advertise online. Google adsense allows you to put code in your website, blog, etc and start making money. The way google adsense works is whatever topic you are talking about, the ad that is placed on your website compliments it. For example, if you have a website that has lots of details about a fishing excursion you have recently went on, then the ads will probably be for boat websites, fishing gear, and things of that nature.
2. Also if you run a very established website, or even if you do not, some companies will pay you to place their link on your website. Many websites can make hundreds, or even thousands a month, just for having a link to another website on their webpage. So even if you have google adsense and no one is clicking, you are still guaranteed the money that the other websites are offering you. A good idea is to check with local businesses or there are many great places to find people wanting to rent space on your website online.
3. Even the emails you send out to your subscribers can make you money, and lots of it. This is another place to place ads and if you have a large amount of people on your mailing list, you can really receive a large amount a money for merely sending an email. That is why it is a good idea to start adding more and more people to your mailing list. The more you add people, the more amount of money you will make. By making money from ads online, one might not even have to have a job besides running their website.