In his comment, Joseph Price asked if there has ever been a marketing strategy that purposely kept a great product on the down-low to build loyalty through grass-roots word of mouth.
Yes. There have been many marketing campaigns that have purposely rationed the supply of a product to build buzz. Two such marketing tactics come to mind. Disney has used their Disappearing Classics marketing campaign to drive sales of animated classics by only selling the videos/DVDs for a limited time. Krispy Kreme employs a ration the supply approach as they benefit from the pent-up demand for their donuts since their availability is still on a regional basis.