If you have something like your product that would be to be promoted, you have find some advertising agent. Now, If I have a small business, the thing that I must do is focusing in the service and give the best product to my new customer. Because the best advertising and the effective advertising is from mouth to mouth.
In Indonesia we usually see, people operate SOHO (small office home office), the product they release like furniture, restaurant and many more. Same with St. Louis HVAC that operate the small business. The first thing that you have to do when doing the small business is focus to serve the best to your customer.