[jgj]

Twitter solved the problem of dead-easy, publish-from-anywhere communication.

Restricting the length of a tweet solved the (perceived?) problem of having to say something meaningful in order to publish on the web. They removed many of the barriers to publishing and by virtue of getting a large user base solved the problem of reaching a large, captive audience for free.

More than anything, they solved the problem of there being no platform in existence that was adequately public, connected, and pointless enough to contain the terse, unsolicited musings of the modern human mind.