Ashman, adding to James's explanation "e" email was the first BIG HIT and many things steamed from that.
successes are ebay of course, in Australia eway as a payment gateway seems to be doing well
given James's examples they all seem to suit a common theme "totally electronic" totally being the primary word, step outside that and I think you may have difficulties in making it work.
eshoes , etrampolines come to mind
but then others would say the "e" is short for online and not electronic so anything is possible.
eharmony would be a good one, but its got $$$$$$$$$ behind it.
tim