I have. After running our blog for around five years, I saw some interesting books at Urban Outfitters and thought that it would be a good time to reach out to a publisher to create something similar. We ended up writing a book of 25 stories that we'd already written about on our website, however, we spiffed it up a bit for the book and had to obtain permissions and sign contracts. It takes a few years for the whole process from the start to publishing. Our book was released this past March. To answer your question, there is no doubt that our publisher considered my unsolicited email because we already had an established blog. It helped that she had already heard of us. We still needed to pitch our ideas at a lunch meeting and have it accepted by their team upon review. Writing a book is a time consuming process versus writing a blog post, but it's pretty neat once it's physically finished. Here's our book: https://www.amazon.com/Love-25-Heartwarming-Celebrations-Humanity/dp/1452139849?ie=UTF8&*Version*=1&*entries*=0