Shares of IBM (IBM 1.39%) are down 5% today after the company announced that it missed sales estimates by a whopping $1 billion. Of course, as Motley Fool One analyst Jason Moser points out, the company still generated almost $24 billion in sales this quarter, but the news certainly doesn't help IBM's case. According to Jason, the company has suffered a tough 2013: IBM only met earnings estimates thanks to a tax benefit, sales in its international markets were down, and sales at its hardware division weren't strong. After seven consecutive quarters of missing sales estimates, Jason is a skeptical about IBM's future.