Two decades ago, Amazon went public as "Earth's biggest bookstore" — a description bold enough to draw a lawsuit from Barnes & Noble, which claimed that Amazon was inaccurately calling itself a store.

"Barnes & Noble was looming as a big competitor," said Tom Alberg, an Amazon board member who invested $50,000 in 1995, shortly after Jeff Bezos launched the website. "Amazon was an interesting start-up, but it was still very much a start-up."

As Amazon celebrates the 20th anniversary of its IPO on Monday, the company is worth more than all but three U.S. companies and is 800 times more valuable than Barnes & Noble. Alberg, who bought his shares at 33 cents apiece, has seen them appreciate to $961.35 as of Friday's close — and that doesn't account for multiple stock splits.

Nothing about Amazon's growth has been typical. From intentionally operating without much profit while whacking every retailer, to turning itself into a major force in enterprise computing and simultaneously creating a voice-powered home assistant, Bezos has made it clear that virtually nothing is off limits.

Way back when Bezos was taking the company public, he was already defying convention.

In early 1997, Amazon was coming off a year in which it generated less than $16 million in revenue. But in March of that year, Bezos gathered his top brass as well as the underwriters and lawyers together in Seattle to get an IPO rolling.

'You could feel the excitement'