[justinhj]

At some point you start losing users who are affected by apps they use suddenly not working any more. If they care to find out why it makes a bad impression. If it happens multiple times they will think about switching to a rival service. There's virtually nothing keeping users on Twitter if a rival service popped up and their friends started moving there.

[csallen]

> There's virtually nothing keeping users on Twitter if a rival service popped up and their friends started moving there.

That's like saying, "There's virtually nothing keeping people on Earth if we develop cheap, reliable, faster-than-light space travel."

[justinhj]

So you're saying creating a rival service to Twitter would be as hard as creating faster than light space travel?

All I'm talking about is gradual migrations like the ones from geocities and myspace. In the case of those services users had a lot of content they'd created that they had to leave behind. By it's ephemeral nature Twitter has very little of that.

[csallen]

No, I'm saying that the value of Twitter isn't the product itself, it's the people using it. I don't get on Twitter because of the allure of a 140-character-limited textbox. I get on Twitter because it's the only place I can receive regular personal updates from my idols, role-models, and colleagues, and even engage them in conversation. The more people on Twitter, the more valuable it becomes to me.

You can build a rival service if you want, but nobody will use it until it provides value, it won't provide value until people use it.

[justinhj]

By that logic everybody would still be using Yahoo search

[csallen]

You're still missing the point. Search doesn't have lock-in via network effects. If all my friends use Yahoo search, it doesn't make my Yahoo search experience any better.

[justinhj]

Then how about myspace?