As of June last year, Twitter was churning out 155 million tweets a day: http://radar.oreilly.com/2011/07/gnip-twitter-firehose-realtime-data.html http://radar.

As of June last year, Twitter was churning out 155 million tweets a day: http://radar.oreilly.com/2011/07/gnip-twitter-firehose-realtime-data.html http://radar.oreilly.com/2011/07/gnip-twitter-firehose-realt... It's not easy to index find that much fresh data in anything resembling real-time. And with real-time data, seconds and minutes matter.