The owner ascertains if sales increase after special promotions. If a special promotion doesn't increase sales, then the business may be in a poor location or there may not be enough potential customers in the business area. If special promotions don't increase business, the owner must take a hard look at the business. Perhaps there just isn't a market for goods or services offered by the firm. The owner endeavors to discover if advertising is reaching intended markets.
Many small businesses become contented when advertising increases sales.
However, additional sales that do not increase profits need reevaluating. Reaching a market other than the intended one is probably a stroke of luck rather than an act of planning. It's great the one time it happens, but it cannot be relied upon.