Many new start-ups will need the cash (or backing) to "invest" in losses for some years before they reach critical mass, or establish themselves in their niche. In the tech sector, most of the big successes (Arsebook, Google, Twitter, Amazon) have lost shed loads of cash before turning the corner. US investors seem to have more of a risk appetite for such businesses, so they reap the eventual rewards.
For these reasons, and some others mentioned in previous posts, I can't see (m)any successful new start-ups in what has become a very mature market with huge barriers to entry.