Moore's Law affects the Web too. When you deploy a service over the Web, you change its very nature. Think about trading stocks. For 50 years, people bought and sold stocks the same way. Now the business changes every quarter.
Stock trading becomes software, which means it follows the laws of technology.
So the market regresses to burgers and pizzas, the lowest common denominator. New York creates a critical mass by squeezing everyone together. That's what the Web does. You've got between 20 million and 50 million people squeezed onto one network. That creates the opportunity for an explosion of niches.