First of all, I need to declare, SMS Spam here is refer to those free promotional message, not those unethical premium SMS(es) services, that charge user per receive. Also, as long as the content does not violate ethical and law regulation, e.g terorrist, race issues, raise conflict, etc.Flashing back in time,where sms just a new-comer service, sending an sms cost about one meal, people found it very effective way to communicate. As it getting popular, telco company along with some creative people start to making business based on this.
And anomaly, the more telco lower the sms cost the more telco got it revenue from. And now, it like almost email, we can send an sms at almost zero cost.
GSM network design to interconnected each other. Like mail server to deliver email, sms delivered by an alien called SMSC. So far, only telco have the SMSC. The best part for spammer is, due to the regulation, sender keep all the revenue, while by right, destination network has to deliver the message due to the regulation.
The world is too big to implement single anti spam policy. So some country start regulate kind of sms. Some even with government law that could bring spammer to court.
But is the regulation effective to combat spam, especially by those well-organized company? Company may change its name. As long as it has the benefit to its marketing, there will always people to send these message in any way. Some company might tear to ground, some can flee away, but sure they will find a way to survive...
So is it effective to set punishment ? I said NO!!
The most effetive way is just block message that telco 'thinks' a spam. Same as my opinion for site blocking. There could by several way of detection like blaclisted Smsc (learning the lesson from email's anti spam softwares). So then just let user to choose which are the best telco for them, especially some country has implemented MNP. Let user decide, whether they prefer protective telco, or they would rather loyal to "more liberal" telco.
Somehow we might found some promo are quite informative. For me, as long as it not costing us, why bother! Just delete the message. Case close and thank you!
