The more often a potential customer hears or reads something, the more familiar it becomes. When something feels familiar, potential customers are more inclined to believe it and think positively about it. 

Repetition calls attention to the information, and also makes it more likely to lodge in your customer's brain. 

With each repetition of your message, your audience naturally grows more familiar with your product and company. A feeling of acceptance begins to grow. As this acceptance strengthens, an affinity begins to develop. They begin to feel comfortable with you. This comfort leads to greater trust, which opens the door to the sale.

Each ad is trying to create marginal differences in consumer attitudes and perceptions. Through repetition, these small differences can build into larger differences, and can often tip the balance in your favor.

The more different sources that expose a subject to the same message, the more convinced the subject will become.

Repeat the same words over and over in your ads. If your call to action is “sign up” do not use words like subscribe or contact us. Use the same word, sign up, every time.