As a data-point, Amazon lost $3b over their first 6 years before turning a profit (citation: <a href="http://www.independent.co.uk/news/business/news/dotcom-delight-as-amazon-makes-first-profit-after-3bn-losses-665950.html" rel="nofollow">http://www.independent.co.uk/news/business/news/dotcom-delig...</a>) .