Making money with blogging is a goal that can be achieved through the use of two business models.
One approach is to sell advertising space to companies wanting to reach your readership, or simply integrate affiliate ads or links to your content.
The other approach is using the blog as a means to improve the image and reach of a single brand by creating positive associations between the blog and the product.
Any of these approaches can be massively profitable, particularly if the creator has taken the time to optimize the blog from a marketing standpoint.
If your goal is to sell advertising then you need to go out and find prospective advertisers or you can simply insert affiliate campaigns in your ad spaces and your content.
Many people turn to ad networks such as AdSense or AdBrite, while other will look into affiliate networks like ClickBank or Commission Junction for ad or affiliate revenue.
The advantage of using a pre-established network instead of looking for individual advertisers, is that you will save a lot of time and effort that you would otherwise have to commit looking for advertisers, and you will be able to cash in almost immediately (provided that you have your blog already setup and running).
This approach can certainly deliver massive results in terms of profits, but regardless of this outcome, it is a fact that your blogging efforts could take you to other territories and at some point you could have an advertiser willing to pay big bucks to have your become their blogger.
Therefore, if your goal is to become a professional blogger if you will, then you must start out as a blogger for profits by setting up your own blog and turning it into a business and commit to working on it consistently until you reach your goals, and who knows, you might end up in places you had never expected blogging for a particular brand in exchange for a hefty compensation.