Two friends and I started http://repeaterstore.com straight out of college. Within a year it was profitable, and within 3 it was doing $3 million in revenue (and about a 15% profit margin). It's pretty much stabilized since then, and we hired a manager to monitor the operation. Most stock is shipped through drop shoppers, we just have 2 customer support people to handle phone calls and emails. Forthe last 2 years we've been working on new, more interesting startups - but having a stable source of income has been incredibly valuable in letting us bootstrap until we could raise funds from VCs. Niche eCommerce can be awesome.