Roger,
I can understand where you're coming from and you have obviously tailored using text for your own requirements, at least you have found a way to use it in a positive way.
The thing is with the "bulk" sms marketing, is that its not all blasted out at one time, but you can set up specific texts to go out at certain times and just leave it as an automated process.
This appeals to me, as often i dont get around to sending the reminder cards out when i should do as we are too busy, and then when it goes quiet we know we should've done it, its a bit of a vicious circle.
At least with this system you can set it up and let the reminders roll out as & when, leaving you to get on with the work.
In a similar way you can do the same for special offers , but still tailor it to maybe clients you havent heard from in a while etc.
You can also get them to show the text to gain there special offer or discount, there by adding value to the text message you have sent them...
Its probably not for eveyone, but if you do have a lot of customers and not a lot of time to get around to communicating with them its got to be one solution,.....
Steve