According to Opinion Research, what annoys employees more than anything else is poor communication. And unhappy employees can do more damage to your business than you might imagine. Opinion Research practice director Terry Reilly says that beyond delivering shoddy customer service, disgruntled employees are less likely to recommend your company as a great place to work, which will hurt recruitment efforts. Reilly says communication can be the Achilles' heel of your organization or it can be the centerpiece. Here's what Reilly recommends to improve communication between management and employees.