If you win a job at any commercial business from a dentist's office in a strip mall to the Sears Tower, you should consider having inexpensive coasters made with a message like "your space has been protected by XYZ Tint against (insert protections here)". The coasters cost a few cents, they will stay on their desk for several months, and the building owner gets kudos for spending the money. It's a good idea to get permission from your customer but make sure they know it will make people think more highly of them if they spent money on protection. You can do pens as well but pens don't stay on their desk and pens are pretty expensive (not to mention if the pen doesn't work well every time they will assume you don't either!!)