Actually I was surprised at the cuthroat nature of the competition in this business. So be prepared for some unpleasantry amongst your competition.
The bottom line is people on the web shop for price, so whatever you can do to keep your prices low, do it. But prepared to offer service like you're priced like a brick and mortar store, because the second you offer cut rate service, it's going to come back to haunt you.
If you can find a niche that works, run with it, you don't have to be all to everyone. And don't start out running your business for cash flow, be prepared to reinvest every dime back into your business to grow it. That's probably the worst mistake any small business owner makes. Keep your day job.