It's getting difficult to get ahold of one's client base without somehow offending a good chunk of them. The value of acquiring a customer is so high in today's market, that great pains should be taken to avoid offending them.
Traditional methods of getting the word out to the client base is to
send flyers, direct mail, even phone calls to your customers, often resulting in the loss of customers rather than any increase in sales. These methods are wasteful, environmentally irresponsible, and just plain rude.
Enter the vibrating pager card. Printed on one side of the card is your business contact information, and perhaps a company logo complete with colors, textures,etc. On the opposite side of the card is a liquid crystal display that can either be blank or, for the deluxe model, can display current date/time functions as well as a calculator.
The card is equipped with a radio reciever capable of recieving signals over short distances. When the cardholder is in the neighborhood of your business establishment, and you choose to broadcast a signal indicating you have a special on X or Y item, the card vibrates gently in their wallet, announcing that it has a brief message for you on it's LCD screen. (The beeping model was rejected during test trials as it caused too many social mishaps, particularly so for escort agencies)
When the customer enters the store, there will be a discount offered for turning in the current business card for a freshly recharged one, completing the cycle of business contact to business deal.