(OCRegister) - Annette Alvarez-Peters is the most powerful wine-industry person you've never heard of. But any vintner can tell you exactly what she does: buys more wine than anyone in the world. Alvarez-Peters is Costco's principal wine buyer. She helps them sell more than $1 billion worth of the stuff every year in 337 of the big-box stores in 34 states. Costco is the sixth largest retailer in the US and number seven in the world. Alvarez-Peters' influence on the industry is profound – not just with winemakers but with other retailers as well. She is in charge of setting prices on wines, and those numbers largely determine the market value of that label. Other much smaller retailers are forced to match or come close to the company's price.