i believe their point is that twitter has an open API and encourages app development on top of its platform everywhere it can, but it simultaneously will pick a golden app that creates a huge barrier of entry to the next "good idea" in that area.But if Twitter decided to implement their own redirection service, there would be no problem, right ? As in, would you still consider that as an innovation barrier ?
I know a lot of the innovation for url redirection services should be looked for in the data mining area, and you need lots of data for data mining. But these tr.im posts all give me the impression they feel like they're entitled to a share of the traffic Twitter generates. They're not, and never will be. Twitter is entitled to decide what they do with their traffic. They could've implemented their own redirection service, they didn't, and decided to go for a single url redirection service. Perhaps precisely to keep the innovation going in that area (url redirection is Bitly's core business, thus they will take the data more seriously), while on the other hand keep the service reliable and predictable.
If your entire business depends upon the grace of a single company, and you don't do anything to break your business out of that, you've just got a bad business model which is destined to give you a lot of headaches, and even will make you fail. And yes, I'm looking at you too, AppStore developers. Quit whining already!