If you are blogging with the goal of selling advertising, there are two basic ways that you can go about recruiting sponsors who want to put ads on your site; you can let someone else do all of the legwork, or you can do the work yourself and keep all of the revenue.
Within the first group, many people make money blogging by selling space through Google's AdSense program. The advantages of this program are numerous, as it requires very little effort on the part of the blogger or webmaster to begin raking in profits. However, most people discover that they make less money through this method than they had hoped that their blog would earn.
Selling advertising directly to companies who want to put banner ads or sponsored links on your blog can take quite a bit of time, but it is often fairly lucrative. If you have a lot of contacts in industries that are related to the topic of your blog, you may want to try to go this route.
People who have a strong background in sales and are experienced at pitching proposals can make quite a bit of money by renting blog space to interested companies.
The most serious problem with this model is that you often have to build quite a sizable readership before you can attract advertisers, which can mean that you have to do several months of work before you start to make money blogging.
As blogging becomes a more and more lucrative business, a lot of established companies are considering how they can get into the action. One way that companies are capitalizing on the blog movement is by having blogs that provide a kind of friendly face for their corporation. Often, a company will employ an established blogger to create a weblog designed specifically to appeal to that company's customers and to create positive associations with the brand in consumers' minds. More than one writer who never even dreamed that he or she could make money blogging has been approached by a company and offered quite a pretty penny for this kind of gig.