KEY POINTS
  • Starbucks shares fall in aftermarket trading despite beating earnings expectations.
  • The coffee chain has struggled with sales in the U.S. for several quarters.
  • Investors want to know if the arrest of two customers at a Philadelphia Starbucks has hurt the brand's sales.

Coffee giant Starbucks has bolstered its loyalty program and maintained steady same-store sales growth, but it still hasn't been able to grow at a fast enough pace to placate investors.

Shares of the company slipped nearly 3 percent in aftermarket trading Thursday.