What profit margin do concessionaires strive to receive to cover their expenses?

Business profit margin.

Explanation:

In general, it is defined as the ratio of profits earned to total sales receipts (or costs) over some defined period. The profit margin is a measure of the amount of profit accruing to a firm from the sale of a product or service. ... A low-cost producer in an industry would generally have a higher profit margin.

Profit margin gauges the degree to which a company or a business activity makes money, essentially by dividing income by revenues. Expressed as a percentage, profit margin indicates how many cents of profit has been generated for each dollar of sale.

answer; ///they are able to see how many people have read or watched some part of a commercial;