In today's world - individuals' data is the digital goldmine for any company.
LinkedIn is a publicly traded company (LNKD), like any publicly traded company their main goal would be profits, plus assets like customer data, etc.
This info can be seen in their financial statements: http://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CI...
Nowadays it's common practice for our digital footprints and identities to be designed/built/directed so that before we can gain access to a company's services, data or content that we would need to read and agree to the terms & conditions and the privacy policies, etc.
This info can be seen in LinkedIn's:
Terms and Conditions http://www.linkedin.com/legal/user-agreement?trk=hb_ft_usera...
Privacy Policy http://www.linkedin.com/legal/user-agreement?trk=hb_ft_usera...
Cookie Policy http://www.linkedin.com/legal/cookie-policy?trk=hb_ft_cookie
What, you mean I'm supposed to read those things? Yes.