The term was coined and defined by Jay Conrad Levinson in his 1983 book of that name, Guerrilla Marketing. The best way to understand it is not in terms of specific strategies but, rather, as a mindset in a ferociously competitive situation and you have severely limited resources. Here are two true stories.
Example #1: There was a family-owned barbershop that found itself in competition with a franchise that opened across the street, offering “Haircuts only $5!” as a special introductory promotion. The two barbers, father and son, could not afford any advertising and had to charge at least $15 a haircut to break even. What to do? Finally, the father came up with an idea and hand-printed a sign to hang in the window: “We repair $5 Haircuts.”
Example #2: Another family saved up its money and invested all of it (plus two loans) to open a pizza parlor, in direct competition with franchises of national chains and with almost no money for advertising. What to do? Finally, the Italian grandmother who provided the recipes also came up with an idea. It worked. What was it? Place a small ad in the daily newspaper offering a 50% discount to anyone who brings in the Yellow Pages listing where to buy pizzas. Those who did also received a small magnetic business card (to attach to a refrigerator) with the pizza parlor’s name and telephone number.
David chose not to wrestle Goliath; rather, he slew him with one small, carefully selected, well-placed stone. In 1588, Queen Elizabeth’s “Sea Hawks” did not engage the Spanish Armada directly; rather, Hawkins, Frobisher, and the other captains took full advantage of the speed and agility of their much smaller ships using a “hit and run” strategy. With all due respect to Jay Conrad Levinson, I think the best explanation of the mindset needed for Guerilla Marketing is in Sun Tzu’s The Art of War. The “rules of engagement” for that mindset are deception, application of maximum force where there is least resistance, and timing.