That's the great thing about O'Reilly Safari, you can easily have them all just a tap away for the price of a subscription. I love my collection of physical O'Reilly books, but I doubt I'll buy too many more.
It's a win/win. They've lost some print sales and likely gained a subscriber for life.
Just Googled the "O'Reilly Data Science Kit" mentioned as one of the prizes and it looks like a really good deal!