A big part of the process of getting published these days seems to be networking with famous authors, agents, editors and publishers on Twitter. This assumes, of course, that famous authors will care who you are and allow you to transition from "fan" to "follower" to "friend". If I were super-famous and had hundreds of people clamouring for my attention 24-7, I think I'd be selective about who I allow to monopolise my time. I don't have time to be online and interacting with an ever-growing swarm of bees, each of whom thinks they are my NEW BESTEST FRIEND EVAR! and really wants me to please read their manuscript and put in a good word for them with their publisher/editor/agent. It sounds like a lot of work because it is. It is the process of becoming someone's real friend, which takes time, and is not always successful.
Mokalus of Borg
PS - Well, actually, it just means becoming a professional acquaintance, which is a bit easier.
PPS - But still not something I would have the energy for from their side.