Amazon went IPO 2 years after it was founded, and had not made a profit in those years. The company went on to lose money for seven more years, until in 2003 when it laid off a seventh of it's employees.
Of course, by undercutting its competitors to lure in buyers, then giving away big discounts to sellers for using their platform, they became sufficiently dominant that when they pulled the rug, both sides were more-or-less stuck with Amazon's monopoly.