One of my favorite blogs is The Daily Coyote, where photographer Shreve Stockton documents her life in Wyoming raising a coyote her friend rescued and gave to her when it was a puppy. My preferred way to read The Daily Coyote was from the beginning, clicking back to the early days and working my way forward a few pages at a time. Gradually what began as a photographic journal became a story, and sure enough, Ms. Stockton got a great book deal.
What I love about this is a validation of the process of blogging as a way to work through ideas with an audience, and of letting them take natural shape. Your blog need not have millions of readers. My Booklab blog has only seven, but they are all dedicated. Instead, the blog is a way to socialize ideas (thanks to Gary in one of my scholarly groups for that term), and to get comfortable with them in an environment that's a near-perfect combination of scratch pad and microphone on stage. I believe that she did end up with zillions of readers, but her audience grew naturally as the blog matured.
Shreve Stockton sells petrified squid that she finds on her property in Wyoming (she says this is legal). I bought some and it will sit in a bowl on the mantel above the fireplace at Booklab as a reminder to anyone who asks that blogging is actually real writing, and it can lead to very real books.