A few years back, we went from what had been a virtual office to actually having a real office. Yet, since the company had been virtual for a while, we've maintained something of a hybrid between a virtual office and a real office.
Not everyone goes into the office all the time (some of our employees aren't local, though the majority of them are).
Some rarely go into the real office at all. Still, there are days when we do try to make sure that everyone's at the office, and that can be quite useful.