Word of mouth is still one of the best types of advertising you can have. It is effectively happy customers sharing their experiences with your company / your products or your services with others. Word-of-mouth advertising is important for every business, as each happy customer can send many new ones your way. Unlike many forms of advertising, it will not cost anything and many people feel happier using a company that has been recommended to them by a friend / family or business college.
In order to gain customers through word of mouth advertising you need to ensure that you offer excellent customer service and that any issues that do arise are dealt with quickly and professionally.
You can also ask your current customers for reviews which you can add to your website or ask them to leave reviews for you on Google for example, which again is advertising your business through word of mouth.