If you're a delivery company like DHL, how could you best advertise your services at a low cost while sticking it to your competitors? How about getting them to advertise for you?

In the video above, we see how DHL got FedEX and UPS to ship packages for them that were actually advertisements for DHL in disguise. The video is a little more than a minute long and gives us the lowdown on this bit of Trojan advertising.

The first step was to get the competitors to deliver packages for them. To this end, giant packages were wrapped in thermo-active foil and then brought down to a below the freezing point. This made it so that the packages looked blank, without any bits of text on them. Once the packages were out and about, the foil would revert back to its original state and would say "DHL is faster" in bright red against a yellow background.

The best part was that these packages were supposed to be delivered to addresses in the area that were not very easy to find, ensuring that the advertisements would be present for all to see for very long periods of time. It seemed that the marketing worked most of the time, except for one instance in which a UPS worker taped up the text so that the advertisement wouldn't show through. Still, you have to hand it to DHL for coming up with a unique marketing strategy.