If you're creating a Photo Book in Blurb's BookWright software you have the option to remove or leave in the Blurb logo page that will appear at the end of your book. Removing the logo page increases the price of the book.
You can remove or leave in the logo page when uploading your Photo Book, as seen in the screenshot below. The logo page can be white or black, with a blue Blurb logo.
You won't see the logo page when previewing your book since it's added during printing. You also can't add your own content to the logo page but the logo page doesn't apply towards your page count. For example, if you design your book with 40 pages and you leave in the logo page you'll pay for 40 pages, not 42.