In my industry (PTC/GPT) Reputation/longevity are really important. There are fly-by-night sites all the time, and the fact that I have been online for over 3 years is really something all the new sites can't compete with for a long time. Of course, you have to offer competitive rates, but longevity is something they just can't buy.
Something that I deem a competitive advantage is the fact that for my business, I usually produce my services on my own versus using a reseller like competitors. This means I can set my pricing to how I choose thus making it lower than my competitors.
Thanks. Perhaps at some point I might need some designing that reflects that I'm the kind of person who gets my work done even if my Internet at home is disconnected. LOL