Within a few business days it will be added to the Ingram catalog, which is available to retailers worldwide. At that time, your book will be available for special order from bookstores in the Ingram network, and for online bookstores to list and sell on their website. Amazon tends to pick up new content more quickly; other retailers can take longer, as long as several weeks. Blurb and Ingram don’t have control over when a retailer displays a book.
You should also think about ways for you to market and promote your book to generate interest. We have some great ideas in our blog post.