Social Footprint

As someone in advertising who is knowledgeable (and aware) of the effects of social media, I wanted to explore my social footprint.
I have a facebook, twitter, Reddit, pinterest, linkedin... account, and they all seem to be clean, but they're not focused. My facebook and personal twitter account are not only to keep in touch with people, but also to network. Via both sites, I've gotten jobs, found places to live, and sold various items. My Reddit account has solidly gotten me jobs, but still gives me the freedom to explore lots of things (without consequence). Pinterest is still new to me, but I am LOVING it!!! I can't say enough good about this site. The only negative thing is that I don't think I'll ever get offline.

LinkedIn is where I draw the line. I try to utilize LinkedIn to the max, but I find that it's particularly difficult. You build up your network to find people who can more or less be references. Supposedly the site gets you jobs and connects you to strangers, but that's not the case. Every time I try to connect to someone in a useful, meaningful way, I can't. They are "outside" of my network. How do I bring them in? You can't send them a message via LinkedIn without an e-mail address, but why not just e-mail? I find LinkedIn to be excessive and, frankly, a waste of time.
I'm about ready to delete my account.