Net gain

The internet has produced many a myth in recent years. I remember going to an investment bank presentation two years ago and hearing how Amazon.com's then-colossal $30 bn valuation was based on a market-sizing exercise that began with a potential customer base of several hundred million people. Today that valuation method has been consigned to the dust heap.The reality - as many an internet retailer has found - is that reaching large audiences is far harder than was originally thought and