To start off with, I'll start with Google’s Adsense. Google trawls your site and pages and determines which of it’s adverts are most suitable for your page content. By peforming this it attempts to show adverts that are most likely to be related to your blog's visitors. Your site then makes money when your visitors click on these adverts to view advertisers - with the majority of these clicks earning you cash. Your income is determined from how many clicks your adverts are likely to get and what subject your website concentrates on. A variety of subjects earn a lot more per click than other subjects.
Another popular system is Amazon. With this system you can advertise specific items from within their catalogue or you let their system put up their choice of items from your chosen keyword. You just choose a keyword and they show the books (or other ranges, if you prefer) that are appropriate to that keyword. On a blog this probably means just using one keyword to cover the whole blog, but that shouldn’t be an issue. You can also put on show more specific links on individual posts. Here you are earning money every time a new visitor clicks through to the Amazon website and then goes on to buy a book.
ClickBank is seen as a popular alternative, this time selling electronic downloaded books. As with Amazon you can show slected products or use a frame that shows all e-books that match to a keyword. Again, you are earning a payment with every purchase made coming from a click on your site.
General affiliate schemes are another opportunity, but I highlight the above three systems as they offer something that most of the others don’t offer - they aren’t geographically dependent. Most affiliate schemes are only paying for in traffic from their own country, as distributing to another country causes headaches. Google gets around this by displaying adverts only related to the country the visitor is from, whilst ClickBank can easily sell to most countries, as it is selling the products electronically. But if you are very specific and not receiving many visitors from abroad, then there are no doubt a whole choice of affiliate schemes for you to join and take part in.
Lastly, there are a wealth of pay per post web sites. Not without their own issues, here you earn money for writing a post within your blog that is a referral to another company. The income vary, depending on the campaign and your own blog. But you can usually only become a member of such services with an established blog. Blogs must be typically 90 days old. The fee your blog can earn depends on its subject matter, the advertisers and how many paid posts you are able to write. If you want to know more about how to make money with a blog, read more details about these ideas at the blog.