Book of Stamps

I was in the Post office the other day buying a book of stamps. I guess it has been a while since I have bought stamps because I was a little shocked that a book cost $8.10. Although I understand the USPS provides grate value - I started thinking about the business model. With online bill pay, email, etc. the industry is transforming and the perceived value is decreasing. I wonder what the post office will look like in 50 years. How will they transform to stay competitive?