And a farm only has value when there are potatoes to harvest. But you gotta plant and tend the potatoes.
So to the extent that LinkedIn can (or can't) support it, you should look at LinkedIn or wherever as something to maintain, for the day when you are looking for a job.
Why should a person maintain their LinkedIn profile, if they're not actively looking? Wouldn't it make more sense to only update it when they decide to actually look for a job, and not waste time/energy/spam-dealing-with before then?
As a person working in the IT industry for more than a decade, being intimately involved with several major Open Source projects in demand, it sounds debatable (perhaps even wrong), as many in demand skills last longer than fads (eg PostgreSQL clueful-ness).
So, what you're saying doesn't sound right to me. :(
Thoughts? :)