Small business owners, especially those without employees, tend to wear many different "hats" in their companies and are often rushed and overworked. Sometimes the unfortunate result is "mediocre" service. And even if you do have employees, they may be providing less than stellar service to your customers. Customers tend to not complain about "mediocre" service, since that is what we as a society have been conditioned to accept. So when a company provides a "great service", it will be remembered, and will help to solidify your company's reputation. A company with a proven reputation and excellent customer references can generally get more business (and even higher prices) than a competing company that provides only mediocre service.
What are some qualities that comprise "great service"?
Most importantly, you must provide exceptional customer service. This includes, but is not limited to, keeping appointments, not running late (or calling if you're going to be late), following through on promises, not trashing your competition (which can make you look petty and underhanded), calling customers back in a timely manner, and doing everything you can to resolve issues or problems that the customer may have with your work, employees, etc. Exceptional customer service means going the extra mile, taking the time to explain in detail the work you're going to do, answering questions honestly and thoroughly, and even helping to educate the customer so that he or she can make informed decisions. Although it may be tempting to "sway" a customer to purchase more services than he or she may need, resist that temptation. The customer will appreciate your honesty, will be more likely to refer you, may become a repeat customer, and may end up purchasing those extra services anyway.
Great service also includes the expertise and knowledge to get the job done correctly and completely. The best customer service in the world cannot make up for work that's performed improperly or incompletely.
You need to actually "care" about the quality of your work and your customers' satisfaction. If you're in business just for the money and you truly don't care about your work or your customers, it will show, and your company is more likely to fail.