Seth Godin posts Don't Sell to Bar Owners, something that, despite its odd title, has relevance to winery owners and sellingwine:
The universal lesson is this: every business has customers. In order to grow, you either need to sell more to those customers or find new customers....The biggest problem marketers make is misjudging their audience. The see the size of the market, but not its true nature: Their accessibility and eagerness. Their worldview and motivation.
You've really got to find the 1,000 True Fans of your winery, the market that is eager for what you have to sell.