I'm curious why Twitter are OK with this: it seems like a core bit of functionality for them to control. Is there a backstory to Gnip? This is the first I'd heard of them.
Gnip has been around for a few years, but re: backstory, this post from our CEO Jud lays things out pretty nicely: http://blog.gnip.com/we-believe/ (disclaimer: I work for Gnip).
GNIP has been reselling the real-time Twitter stream for well over a year now. Presumably, part of what you pay for the service actually ends up in Twitter's pocket.
Yeah, I assumed they weren't doing it out of the goodness of their hearts - just that analytics seems like something they'd want to keep a handle on themselves.
Here's the initial Gnip announcement from almost 2 years ago where Twitter somewhat explain their rationale: