I'd assumed that by now it is common knowledge that if you are building any sort of social software, the users and community are more important than the technology. MySpace is probably the biggest example of this phenomenon. I was reminded again that not everyone gets this fundamental truth about social software when reading Dave Winer's post B. Mann loses it where he writes

He says he lost it when he read my post about federating Twitter last night. He says "Forget Twitter. It has a bunch of users, that's about it." And goes on to say someone should rebuild Twitter using Jabber.

But having a bunch of users is very important feature. You can't just skip over it as if it didn't matter, because imho it's all that matters. Jabber is a good technological foundation. But we've learned over and over that that isn't enough to get people to use something.

So many people who know technology think they know better than users. The trick is to forget that and just go where the people are. Jason wants to use Twitter. So do a lot of people. That's good enough for me.

An example of a recently debuted service that didn't pay attention to this lesson is Truemors. VentureBeat covered what happened to the site when it launched in the article Truemors, the Twitter for rumors, smothered by spam which stated

Guy Kawasaki’s new company Truemors, has launched, and it is a sort of Twitter for rumors.
However, the site has been overrun largely by nonsense and spam — for example, rumors that a war is going to break out in the Middle East, to spam for “Sportiki” and “Dafun.”

Here’s how it works: You can call in a message to Truemors (or you text, or email), and leave your rumor. Kawasaki, a long-time consultant and investor in start-ups, was philosophical about the negative response even in the chatter leading up to the launch.

There’s a lesson here. The site had no focus, and thus no community. A moderator is also a good idea for such sites, because otherwise spam will prevail.

That's pretty good advice from VentureBeat. You have to seed a fledgling social site with the kind of users you would like to have, preferably the folks working on the site should be using it regularly at least until it hits critical mass and can survive without constant parental supervision. There's a lot more very good advice on running a "social" site in Matt Haughy of MetaFilter's post Some Community Tips for 2007.