If you have a server at home, this can be good for local web development or testing. However, you might want a dedicated hosting provider to handle your customers. Chances are, your hosting provider has a substantial investment in servers, maybe costing more than you could afford. In other words, some hosting providers have spent millions on infrastructure. Now, unless you have spent anywhere near the same money, you are better off going with an off site dedicated server, rather than relying solely on a home server.