One way blog hosts are able to provide free blogging is through paid advertising. You get to host your blog for free, but in exchange, you agree to let the host place paid advertisements alongside your blog content. Ideally, the ads will be targeted--or of interest--to your blog audience. Bloggers visiting your site will see the ads and click-through to the advertiser's site. Offering free blog hosting is also a deliberate marketing strategy that goes something like this: If you start a blog using free hosting and stick with it, chances are you'll eventually tire of the limitations of the features and administrative tools available with the free service. Once you reach that tipping point, you'll upgrade to a fee-based hosting package that includes more features and greater flexibility. Voila! The blog host now has a new paying customer!