True it is.

But you can always join your local gateway for sending SMS via IM, but you still need to pay monthly fee.

Beware of those free IM->SMS gateway service you could find on the internet. It needs you to sign contract with fine print that actually permit them to charge you by *receiving* their SMS(and they don't need your credit - they ask your mobile carrier for the fee). I've seen reports of those fraudulent cases in the local news.