Advertising is an engine of trade, but at the same time a rather costly way to attract customers. Today there are many ways of advertising, including SMS mailing, but not all of them bring the same result. In the abundance of ads, your ad may get lost, although theoretically, everyone who saw it could become your client.
The goal of any business is profit, and as you know, most of the profit is brought by regular customers by re-buying your goods and advising you to your friends. Therefore, it is important to reinforce their confidence.