SMS ringtones and SMS porn are all premium services and naturally are not be affected by a 3 cent transaction fee. This hurts companies that send out free opt in SMS alerts and subsidize them with advertising at the bottom of the message. Up until now, their model was to build up scale which gets them a lower per message fee with the aggregators. However even with large volumes their margins are a few cents at best. This 3 cent "transaction fee" kills them.
Back when phones with monochrome displays were common, I did indeed see adverts for pornographic wallpapers, which, as far as I know, were submitted via specially encoded SMS. These days I'm guessing they use MMS.
