AT&T Raising SMS Rates to $0.20... When Will We Move to Email?

Starting March 30th, AT&T is raising SMS and MMS rates by $0.05 to $0.20 and $0.30 respectively... which is absurdly expensive considering that the actual cost of an SMS message to the carrier is close to nothing. Slashdot and DSLreports.com each did analysis stating that the effective marginal cost of a text message is zero.

So while our phone bills are growing, I ask:

Why is sms still the instant-communication of choice?

I find email, Gtalk and Twitter to be equally effective. Anyone who uses a Blackberry or iPhone (or email capable phone) has access to information instantly and email provides more flexibility. The only benefit of text messages is that you can set dedicated alerts to them (vibration, sounds, etc). Is that worth it?

Gtalk is fully integrated into my Blackberry (or your iPhone) and allows real-time communication, full alert customization... and oh yeah - it's treated as data (rather than $0.20 a message).