Reach a Much Larger Audience
When you place an ad on a truck, you are given the opportunity to reach a huge audience. A great deal of the population spends some amount of time in their cars each day. Because of this, you are going to have a very high chance of someone driving past the truck that is displaying your ad. Since the point of an ad is to have it seen by as many people see it as possible, this is going to be a great choice of ad location for you.