Ning keeps growing. Over half million networks now.
readwriteweb.com
readwriteweb.com
This duplication clearly hurts Ning: because of the network effect, merging two networks doesn't make it twice as useful -- it makes it four times as useful. I'm sure Ning knows this, but they aren't able to do anything about it because if they change the design, and the pace of network creation slows down, their investors might look at the chart and panic.
Ning is unique in their space, so right now they don't have much to worry about. But they have to be really careful about the fragmentation or else at some point they will have more networks than users and the useful activity will get drowned out in a sea of noise.
But, given their 500,000 networks #, that means that they are getting.... 7 uniques per network per month? Assuming zero overlap?
And uniques are a bad metric, too. They have 1.5 million indexed pages ( http://www.google.com/search?q=site%3Aning.com ) - I'd wager 1/3 to 1/2 of their uniques are from long-tail search queries. And I'd further wager than 50%+ of those uniques BOUNCE (http://en.wikipedia.org/wiki/Bounce_Rate), so exactly what percentage of those 3.5m uniques actually do ANYTHING? Bounce rates of 30-50% for search engine traffic are pretty good, so...