Guerrilla marketing is an unconventional system of promotions that relies on time, energy and imagination rather than a big marketing budget. Typically, guerrilla marketing tactics are unexpected and unconventional; consumers are targeted in unexpected places, which can make the idea that’s being marketed memorable, generate buzz, and even spread virally. The term was coined and defined by Jay Conrad Levinson in his 1983 book Guerrilla Marketing. The term has since entered the popular vocabulary and marketing textbooks.
Guerilla Marketing involves unusual approaches such as intercept encounters in public places, street giveaways of products, pr stunts, any unconventional marketing intended to get maximum results from minimal resources. More innovative approaches to Guerilla marketing now utilize cutting edge mobile digital technologies to really engage the consumer and create a memorable brand experience. Great examples of this type of marketing include products such as T-Shirt TV T-shirttv.com, the mobile media chariot or video segway, and ice cream truck advertising, created by Guerrilla Marketing companies like Brand Marketers. – Wikipedia
Here are some examples!