Since a social network's value increases at something approaching the square of the growth rate in users [1], it makes sense for wealthy backers to be active participants early on -- which is probably why Peter Thiel has a LinkedIn profile and Tom updates his Myspace.
[1] And a user's incentive to join correlates with the average desirability of other users, in terms of whatever the network focuses on. Link-finding ability for reddit, popularity for Facebook/Myspace, sexual attractiveness for dating sites, disposable income for business networking sites, etc.
[1] And a user's incentive to join correlates with the average desirability of other users, in terms of whatever the network focuses on. Link-finding ability for reddit, popularity for Facebook/Myspace, sexual attractiveness for dating sites, disposable income for business networking sites, etc.