When you become the "first business" that customers think of first when they have a need or serious problem that must be fixed, you would be in a good position to increase sales revenue with very little marketing.
So becoming the "first business" should be your highest business priority.
To become the "first business", you will need to focus on customer service before a customer becomes a customer. That means to go above and beyond everyone else from the first initial phone call or meeting to ongoing prompt and professional resolution of issues. You will need to be willing to sit down and listen to your customers and be able to communicate in simple language that your customers can understand. To solve your customers' problem, you will need to develop expert knowledge about your product and/or service, your competitors and your customers. Most importantly, you will need to consistently connect with your customers on a personal and professional level.
If you implement these strategies, you will soon find out that you are the "first business" that customers will think of and call upon.