I just noticed that there is now a limit of outgoing SMS messages from Twitter to your mobile phone. Current number is 250 per week. Apparently, this was introduced some time ago (a couple of weeks?), but only noticed it now. There is no mention of it in Twitter Blog.
Twitter is not currently running any ads or membership services, so it’s hard to see how they can pay for all those outgoing SMS, except via a few investments that they got. So, this limitation was somewhat expected. It’s still sad to see it come, even though it’s high enough for most people not to hit it at all.
I think that Twitter will (or at least should) introduce some commercial packages with some extra features and several options for SMS limitations. 250/week for a free account sounds like a reasonable amount.