Why Google+ will succeed wildly. At first.
goodexperience.com
goodexperience.com
"If you look at how people use their horses, the majority of them don't go over 15mph."
We'll see what happens with G+ vs. Facebook. I suspect there will be feature list battle coming up. Aside from patents, there isn't much stopping Facebook and Google from stealing each other's improvements.
There's still a question, though, of whether people will think it's worth the effort to categorize all their contacts. I'm not sure how many will bother.
But what they mainly present me with is three contacts at a time, always visible, and it just takes a couple clicks to categorize one. Then I get to see who pops up next. Every time I go on g+ I do a few of them without really thinking about it. And if you saw my hard disk you'd see I'm not much for organizing at all, generally.