Pros
Very smart, friendly, outgoing people from great schools and past companies.
Cons
People aren't promoted based on merit, but on who is better friends with the managers. Check out how many of the first sales managers and directors were childhood friends. Some new reps are hand chosen to get the best territories, and their careers soar with promotion after promotion in short periods of time without putting in the honest and hard work others put in. If you can be on that list, LinkedIn is a dream come true. If you aren't, you're going to make your managers rich while they promote people with worse numbers than you consistently. You would think that in sales, where closed deals and hard numbers are the only things that matter, it would easily be a meritocracy. LinkedIn proves this is not so.