Business Model for Startups: Selling the personal data of users

Yesterday i talked to a venture capitalist about the business models of most of the web2.0 social communities:

1. sell advertising on your site
2. sell personal data and behavioural information of your users
3. sell the platform to google/yahoo/whomever

Sure there are more specific business models depending on the domain of the app (xing’s premium account, last.fm’s model of selling music, etc), but i was impressed about item 2. Selling personal data or sell the platform itself seems to be rather closely related, depending on laws and terms of service of the app. I checked the privacy policies of delicious and last.fm – i’m no lawyer but it seems they made clear they won’t sell users personal data.