Writing paid post is perhaps the most straight forward ways to earn some revenue from blogging. The way pay post works hasn’t changed much; after reaching mutual agreement with advertisers, you write about them, they pay you. And if there is a 3rd party (middle man company) involve, they take cut. Most middle man company provides marketplace for advertisers to look for publishers, vice versa.
If you firmly believe that writing pay post is one good way to revenue from your blog, here’s a list of web services that pays you to write for them. This list will be updated periodically, so if you have a paid post service I’ve missed out I’d like to add them to the list.