Sentence:  The two little bangs meant that he was getting impatient to have a crowd of <WSD>customers</WSD> waited on and that if he had to he would jerk open the door and drag out , by the opposite door handle which she would be clutching , whichever-the-hell clerk it was who thought she could waste so much store time on the pot . 
Meaning of the word marked with <WSD> tags:  someone who pays for goods or services