I haven't tried it myself but it should work since I got a physical flier snail-mailed to me from them:
https://www.snapfish.com/babybook
Use coupon code BABYBOOK at checkout for a free 5x7 Everyday Photo Book (up to 20 pages free). Expires 10/31.
You still have to pay taxes and shipping though.
Also, if you're a new customer, you can also get 50 free 4x6 prints.
I've only used Snapfish twice: once for photos and another time for a calendar. I thought the photos turned out a bit dark, so when I made the calendar, I purposely brightened up my pics a bit and I loved how the calendar turned out. Haven't gotten their photo books before though...