Via TechCrunch, I see that a way for Twitter to make money does in fact exist:

Currently, it costs a lot of money to launch a start-up in the SMS/mobile space — you have to license a shortcode monthly ($500-$1000/mo), pay a SMS gateway provider, and then pay anywhere from $0.03 - $0.05 per inbound or outbound text message. It adds up. But now, if a start-up chooses to use Twitter as a command line to their web service, it’s free (until Twitter starts charging for it).

So right now, Twitter could be in "viral" mode, getting people hooked. Later, they could start charging a nominal fee for the service. Hmm...

Technorati Tags: management, Twitter