One cool thing we picked up at this year's MinistryCOM conference was "bringer cards." It was an idea that Jody Wissing threw out in her seminar. They're business cards that can be easily handed out by people to invite, or "bring" their friends to the next sermon series. In our case, "Unshakable."
We printed 5,000 of these for about $100. Not too bad. People took them by the hand-fulls and hopefully they'll pass them out, leave them on their desk, give them to friends and family...just get them out in the community. A low-cost marketing tool--and who doesn't need that?
