During the early part of the 20th century, a shaving cream manufacturer got an idea for Advertising its new product: They put five-line poems, one line at a time, on various highways, such that each line was just short enough to read while driving along. The fifth line was always the product name: Burma Shave. There were hundreds of different jingles, plus thousands made up by customers. The vast majority of the jingles probably insinuated questionable or obscene uses of the product. The Other Wiki has an article here.