If your customers must abide by certain regulations, try sending them the phone numbers of frequently called agencies. Chris White, marketing director for Environmental Compliance Testing (ECT), based in Rochester, Mass., tried this after getting repeated calls from his customers.

ECT tests the piping systems in hospitals that bring gases, such as oxygen and nitrous oxide, to patient and operating rooms. To ensure that their systems complied with federal regulations, hospitals' directors of engineering would routinely call White with compliance questions.

To ward off time-consuming calls, White mailed Rolodex cards with the numbers of the relevant regulatory agencies ? and his company's name and number ? to the directors of engineering at 2,682 hospitals nationwide. Now, when the hospitals suddenly have a problem or have to prepare to pass an upcoming inspection, "they panic, look up our name, see the agency's number, and call," White says.

ECT now mails about 3,000 pieces several times a year, hitting all the hospitals in its 21-state market. "If your customers need to follow guidelines," he adds, "the cards will help them. They'll be grateful to you, and every time they look up a regulator's number, they'll see your name and be reminded of that."