You say you've tried fliers, discounts and coupons, but you don't say who received them. You need to get in front of all the employees in offices on other floors of your building and in adjacent buildings.
Food is, of course, the ideal lure. I suggest dressing in the garb of a chef or baker and taking small boxes or baskets of muffins or bagels and menus bearing your coffee shop name to every front office.
Ask to see the office managers. Tell each of them that the basket is a gift from your new restaurant and ask them to please put it in their lunchroom. Also ask if you can provide menus for each department. If you're friendly, not pushy, you can win them over.
Question added to topic Marketing • August 13, 2008
I have a coffee shop on the third floor of a business building, with very limited visibility. How can I increase my foot traffic?!
We knew location would be a challenge. We have been open for about 10 months now and have regular customers, but not nearly enough. We work closely with a medical clinic on the same floor, and get a good chunk of business from drug reps. I've tried fliers, discounts on drinks, coupons in the different offices, but nothing seems to attract enough people. For the time being, we don't have to pay any rent because the medical clinic pays for the space. Everyone who tries our products like them, but we need to get more people to try them. Patients are not typically regulars, so it's hard getting new customers.