Even Amazon started without inventory. The website was the Ingram wholesaler catalogue, Amazon displayed 2-3 day shipping and would quickly order the book from

Even Amazon started without inventory. The website was the Ingram wholesaler catalogue, Amazon displayed 2-3 day shipping and would quickly order the book from the wholesaler within 24h. Only after a year of operation they started to directly pre-buy from publishers (top 100 books). I used to work at a similar company. As long as the sales margins are good and support burden manageable it's a decent business. These days dropshippers outsource shipping, returns.