Read this article from Blogging Tips.

“The single most successful technique I have used to increase my blog’s readership is the creation and free distribution of relevant ebooks.

By writing and offering ebooks for free distribution, you offer potential visitors a great incentive to visit (or subscribe to) your blog. What’s more, ebooks have the potential to become viral marketing tools, enhancing visibility of your site and your status as an “expert” in your field.”