Having a virtual office can cause employees to miss out on the social advantage of being in an office. Virtual employees can suffer from the "out of sight, out of mind" effect, in which they could be passed on for promotions or opportunities because they weren't in the office for management to consider them. They also can miss out on networking opportunities which could lead to other options in the company.
Travel Research:Virtual assistants are a great resource for finding hotels, booking airfares and mapping out trip itineraries both for business and pleasure. The assistants can take advantage of the growing number of travel research tools and review sites on the Web. They can also deal with the hassle of navigating time zones when booking or researching international travel options by phone.
I doubt many companies like or prefer that employees work from home. We allow the policy in order to be able to attract employees who would otherwise go elsewhere. We are heavy users of Slack, Confluence and other collaboration tools that make working at home more productive, but they cannot replace the serendipitous interactions that occur while hanging out by the nitro-coffee keg. - Manuel Vellon, Level 11