Employees who access Facebook, Twitter or other social media sites during office hours waste between 15 minutes and 2 hours every work day, resulting in a company-wide 1.5% drop in total worker productivity.
Nucleus Research interviewed 237 randomly selected office workers in 2009 and found that almost half use social media websites during working hours. Very few of these workers – only 13% – could identify a clear business reason for doing so. Instead, almost all the employees use Facebook at work for personal networking reasons. Beyond its adverse impact on worker productivity, Nucleus also noted that Facebook is increasingly replacing email as a means of communication. Because Facebook messages typically are not monitored by companies in the same way that emails are, this practice may open the door to violations of corporate communication policies.
The bottom line? In some cases there may be legitimate business reasons for employees to use social media sites during work, but the benefits do not outweigh the resulting loss of productivity.
Source: Nucleus Research (Social Networking as a Time Waster)