What do you anticipate your client mix to be?:
Whether you're planning on working mostly with buyers or sellers can be the most important factor in whether you need a full physical office or not. Generally, you'll probably find that you're meeting buyers outside the office anyway. Many real estate professionals meet their buyer clients at locations near the area in which they're showing properties. Obviously, there's less need for an office in this scenario.
Sellers however probably will value a "brick and mortar" business location more.
Are you equipped to be mobile?:
Let's say you've done your research, set appointments and you've just met your buyers at Starbucks. They spring on you that they want to add a home to the list that they saw in a homes magazine.
They have the MLS number, but you can't look it up on the fly, as your access is on your home or office computer. You must consider this situation as the norm, rather than the exception. If you want to be mobile, have a wireless computer and even better a portable printer and scanner to do the job.
With agents, have a conference or meeting room.:
Whatever you may think will work for you personally, if you want agents to hang their license with you, have a professional place for them to meet clients.
Generally, those who hang their license with a broker do so because they want a certain level of support and business presence presented to their clients and prospects. At the very least, provide a rented conference room setup with an internet computer for them to use to meet and serve their clients.
It's all about client service.:
As your prospect and client base become more technology and internet oriented, there will probably be less value placed in a physical business location. However, particularly with listings, the ability of the local client to walk into an office to discuss their property will probably always be important.