7 free methods of advertising online.

1. Blog or website.
This one is pretty straight forward, it isn't exactly free but it costs a lot less, you can sell stuff to your readers through advertising on your website if you can get good traffic (visitors).

2. Social media sites.
The fastest the quickest way to start advertising at no cost at all, you can make your own account on any of the kind of websites that allow people to interact with each other and then start posting your advertisements of your products or services to your followers. Ofcource, some websites do not allow straight up advertising unless you are paying for it so you do it in a way that doesn't show its an advertisement, for example, providing your customers with a link and telling them about what the website offers, instead of a large banner.

3. YouTube videos.
Many people post videos and allow other people to advertise just before their video comes up but very few people advertise their own product or service.If you have some great videos or you know how to create good ones, you can start advertising your own business with your videos,

4. Writing for other blogs.
If you haven't got the time or money to make your own blog, you can write for other blogs where they would probably pay you, it would be hard to find a blog that allows you to advertise, but the money earned can be used to promote your products.

5. Answering questions and posting on forums.
There are a lot of websites that people post questions on and need others to answer, but you don't want to answer questions for free or promote forums, you can post a picture of your product or service, explain it and then provide a link after answering the question.

6. Selling a product
If you are selling products, you can post your products on one of the biggest online stores such as Amazon or eBay, you don't have to pay any amount before someone buys your product so it's basaically selling your product with a business that already have a lot of customers. Ofcource, you pay a fee after a sale so you can to calculate the profit.

7. Selling a service.
If you would like to advertise your knowledge and sell it or just simply write on paper, you can be an online teacher and make use of your skills. If you master a certain subject, you can also write assignments for students on certain websites and get paid for it.