Why they are less and less investment by starts-up in internet retail, internet software and social / platform software?
In a first time is important to say that there are 3 companies, that's dominating the industry: Amazon, Google and Facebook. The problem with these companies is that they set up a "Kill zone" for starts-up in the industry. In fact the strategy of these giant of the web is to buy starts-up that have potetial and take the R&D before killing the entreprise and take the concept.
For exemple whe can take the case of Picasa that as been bought by google who take the concept of picasa to create google photos and let picasa with no any update and let it die.