The management guru Peter Drucker once said that the whole purpose of business is to create customers. Businesses do this (ideally) with everything that they do.
Perhaps the most important thing that businesses must do to create customers is to market themselves. This means, of course, that they must advertise in effective ways. However, it also means that they must figure out what sort of product they want to create and what market they want to create it for.
To create customers, businesses must find a product and a potential market. They must then create the product and bring it to the attention of the people in that market. By doing these things, they are creating customers who did not previously exist.