Examples: superior service, expert staff, beautiful facilities, cutting-edge equipment, personal care, great food, affordable
Consider which of your products and services have the most demand, have the highest margin, are easiest to deliver, give you a competitive advantage, lead to sales of other products, etc.
In other words, how much does the product or service sell for, and how much does it cost you to make or provide? This gives us an idea of how many sales you might need of these products to profit from the amount you spend in ads.