When Amazon said they were thinking of an offer in the "low eight figures," Hastings hesitated, according to the book. Randolph writes that Hastings thought that Netflix had "real potential," higher than that offer.
Randolph was fine with the money; selling would let them sidestep the issue that they weren't making money.
But, ultimately, while the two knew Amazon would eventually become a competitor, they decided it wasn't the "right moment to give up."