You're advertising to a passing parade. Different people are shopping all the time for the goods or services you sell, and they'll buy those goods or services from you or from your competitors. Each time a household in your area replaces itself, you have a chance to educate and motivate a new consumer. Hundreds at least, perhaps thousands. Think about it.
People often take their time before buying.
Most people are impulse buyers, but not when it comes to larger purchases such as appliances, cars, houses, college education, etc. A consumer can be in the market for several weeks or months before a purchase is made. Your job is to keep yourself in front of the consumer during the buying cycle. To establish an equity position in the consumer community. Your USP distinguishes you from your competitors.