Pretzel Crisps Grows its Facebook Fan Base With Coupons

What's more revealing is the response Pretzel Crisps got from a second coupon offer. With no media, no status updates, no hype, no blogger network, no advertising, the company switched the coupon from a dollar off to a buy-one-get-one free coupon.

"It was a real surprise to all of us," says Harty. "We switched it overnight, basically in the cover of darkness. Only the darkness proved to shed a little light. One person found the coupon and shared it. From there one blogger found it, shared it and so on. The sharing continued, and over the course of 36 hours our fan base more than doubled from 14,000 to 29,000."