Most people know several hundred people. Create this list for recruits. Referrals from customers and acquaintances. Each person on your warm list has his or her own warm list of people you don't know. Business cards, buttons and brochures.
Most companies offer sales aids that help the cold sponsoring process.
Something catchy will inevitably create interest. If people are bold enough to quiz you about the button, they're probably outgoing and a great prospect. Pass out literature with your phone and e-mail, and use your business cards. Do this consistently. The law of averages says something has got to happen.