This should really read "Gnip offers metered pricing for firehouse of tweets"

This is welcome news. Aside from search engines, no one wants to drink the entire firehose. Why doesn't Twitter just enter the monitoring business itself?

Because they would be (rightfully) accused of attacking their own ecosystem. Because people (rightfully?) believe that they should focus on their core product first and not dabble in somewhat related areas until that is stable. Cf. the backlash when they brought out their "official" apps.

How can Twitter sell content created by users?

They, like every other community site, have a ToS that grants them rights to publish and sublicense user submitted content. They couldn't function without it, when you view a twitter feed with your browser and see sponsored trending topics, they're "selling" content:

> You retain your rights to any Content you submit, post or display on or through the Services. By submitting, posting or displaying Content on or through the Services, you grant us a worldwide, non-exclusive, royalty-free license (with the right to sublicense) to use, copy, reproduce, process, adapt, modify, publish, transmit, display and distribute such Content in any and all media or distribution methods (now known or later developed).

http://twitter.com/tos

that sounds really expensive at $0.10/1000 if you want to do any serious analysis

If you had just spent $3 million on a super bowl commercial, how much would it be worth to you to know the immediate response to that commercial when it airs?

If you would like to find out more about an alternative service to Gnip, take a peak at http://datasift.net and follow us on Twitter @datasift.

Can't work out a lot from the site, what sort of services are you providing as part of the alpha? Is it API access?