Just to chime in on these last few posts...
Most of my jvs, networking, partnerships all stemmed from faceless contact: forums, skype, facebook, emails. Of course, phone calls then occurred but in person meetings were rare.
That being said, I've directly and indirectly made thousands upon thousands from every single IM conference I've been to. I've only been to about 5... each one flipped into high 4-figure quick deals or more commonly low 5-figure quick deals and even 1 6-figure deal. But those same relationships are here for a long time and will develop into even more indirectly.
So...
I agree with Laurie, there's a lot of value to online networking. When done with purpose vs. just "hanging out" and "chatting". (Or at least that's what works for ME).
But you greatly accelerate the process with in person meets. Especially if lunch, dinner, drinks or some down-time is involved with that other merchant/marketer. It's a quick way to build the start of a new friendship and working relationship.