If you live in a city where Peapod is available, you’ve probably seen one of their delivery trucks. You might also have noticed that the online grocery retailer does a great job at turning each truck into a moving ad for their website. In particular, they have prominent branding and a call-to-action right on the truck itself. There’s even a special coupon code that you can enter after seeing the truck. For instance, I saw one that said “Save $10 off your first order by entering discount code TRUCK”.

But once you look beyond Peapod, delivery trucks are rarely used for customer acquisition. Companies like FedEx have thousands of trucks, but all they put on there is a web address — no enticement for new customers to sign-up or a coupon code to help track them.

In fact, there’s no reason this approach is limited to delivery trucks. Anything that customers use outside your physical place of business — from a rental car to a shopping bag — is a strong candidate for inexpensive customer acquisition. Add a little call-to-action and a special discount code, and you’ve got a cheap and effective way to gain more customers.