I don't like sending SMS every day...I use the service only for special occasions or to send quick messages...
I don't care about sending SMS, but if a person I am calling don't answer me, I send him sms with the information I wanted to tel him.
I send sms a lot because I like it, not because it is festival or important occasion . Plus I massively send sms to many of my customs, it is a bit like sending email newsletters .
i still send SMS just to say congratulation for those special moments. it's more cheaper that call one by one. (i send a lot to my friend)