Hi Michael,
I'm sure the feedback that you've had so far has provided you with plenty of ideas but I thought I'd mention another service that you may find helpful.
The fact that you're promoting a SMS service will help if you can target businesses that are already using current technology to promote themselves. For example, a business that currently has a website is obviously aware that they need to be using current technology to promote themselves and are more likely to be receptive to your service.
We operate an online business that allows businesses such as yourselves to purchase keyword targeted lists that are sourced from current websites, online directories and blogs. You can target specific locations and as our lists show who has a website and who is paying for pay per click advertising, you know you'll be targeting businesses that are more likely to be receptive to SMS marketing.
In addition to our list service you can also purchase postcards from our site that we post to your keyword targeted list. These can be based on either our selection of front images or you can upload your own. You can order as little as 10 postcards so it's perfect for sending out just a few to specific businesses.
For more information on how we can help you go to
www.keywordbusinesslists.com, there's a lot of information there that I'm sure you'll find valuable.
Good luck!
Paul