One thing people should realise it will be commercial customers who will require this service, hotels, doctors surgeries, dentists, vets etc. Don't just think you can call in or send them a mail shot and they'll snap your hand off.
It takes at least 7 attempts before the average commercial customer will even have you on their radar. Some marketeers believe its around 20 before they will use your services.
You have to plug away using various media, personal call, fliers, email.
One tip if calling leave them a couple of spotter bottles with your details on. That tends to get people at least asking who they were from and what did they want.