How often do investors receive the grandest of warnings? And how often do those warnings prove relevant and highly accurate? Keurig Green Mountain announced Q2 2015 results this week that showed a continued decline in brewer sales and a steep slowdown in the rate of sales growth for its highly profitable portion packs/K-cups. Total net sales for Keurig Green Mountain grew only 2 percent during the quarter as brewer sales volume fell by 22 percent and portion pack sales grew by only 7 percent.