"Bezos and his wife grew fond of another possibility: Relentless.com. Friends suggested that it sounded a bit sinister. But something about it must have captivated Bezos: he registered the URL in September 1994, and he kept it. Type Relentless.com into the Web today and it takes you to Amazon." -- Stone, Brad. The Everything Store (p. 31). Little, Brown and Company. Kindle Edition.

N.B.: "Today", in the context of that quote, is ca. 2013, when the book was published. relentless.com redirected to amazon.com for me this morning (2021-02-03).