Thanks for your comment. It sounds like you were a very mature and business-focused teenager! :)
While it is really impressive that you had two businesses at age 13, most children were probably not as business-savvy and driven as you at that age.
I don't think connecting with those already in the industries I wanted to be a part of aged 13 would have had a positive aspect on my life, as I changed my mind constantly throughout my teenage years, much like lots of other people.
The worry I have with LinkedIn is the pressure on children to make a decision way too early about their future career. Plus, LinkedIn is for networking with fellow professionals and has always had a clear idea of its identity.
Don't get me wrong, I think resources should be available to all children about potential careers or education paths, but in my opinion LinkedIn is definitely not the right platform for that sort of campaign.