This way every time you have to send a letter you will be getting everyone in that office to see your logo and company name.

Another useful tool you have are your windows, and if you own or rent any kind of building, then your windows are a huge blank canvas for you to market from using window decals. What is so great about these is that you are broadcasting your company to everyone who walks past with absolutely no overheads other than the cost of the buying the window decals initially. If you are on one of the top floors of your building, then putting window decals on the glass will mean that everyone on the streets below will see your logo and read what you have to say, and as more people come and go every day then this would mean you broadcast yourself to a fresh few thousand people every day. Shops and restaurants often already use this, using window decals under their business name to convey more information about what's inside - but why not use this method in offices and other businesses too?