Continuing on my previous post about circulation numbers for the pulps, I found this information in the same article called "The Love Pulps" that Thomas Uzzell wrote for Scribners in April 1938. This is either going to be way more information than you ever cared to know about pulp history, or you'll find it interesting and maybe it will answer some questions. For one thing, it answers the question as to whether unsold copies were returned.
Here is Uzzell's detail on the numbers that are used to determine profit for one issue.
"The rates paid love-pulp writers are not high: their editors make money by not spending much of it. In the boom days of the 1920's, pulp romances brought as high as four cents a word, or around $200 a story. Today, two and a half cents is probably the top; LOVE STORY, for instance, averages around one and three-quarter cents. LOVE BOOK pays two cents, but averages less, while the Wyns pay around a cent and a half.
"In a single issue, the total fees paid authors for an average of six stories, two installments of serials, and space-filling poetry are from $500 to $2500. The ratio of this expense to the total cost of a successful pulp book can be seen in the cost sheets furnished by one of them which totals 128 pages, has a print order of 100,000, and sells for fifteen cents on the newsstands. These other costs are: printing $1400; paper, $1000; engraving, $230; illustrations, $175; editorial salaries, $200; overhead, $100. The total, including an average charge of $700 for the authors is $3790.00
"The publisher sells the entire print order to the distributor for eight and a half cents a copy and is credited with $8500. At the end of the sale period, the distributor returns unsold copies at nine and a half cents each. The sale varies from forty-five to fifty-five per cent. On a fifty per cent sale the net return to the publisher is his credit of $8500 less $4750 or $3750. Advertising space for this magazine is calculated at from eighty cents to a dollar per page per thousand, minus a twenty-five per cent agency commission and staff costs. Allowing $250 as the net on advertising and a similar sum for resale of the returns abroad, we have a net revenue of $4250 and a net profit of one issue of $460."
So there you have it. All that work for a net profit of $460. What I found interesting was the editor salaries of $200. If there were two editors, then you'd guess that they were making $100 each per week. That's $400 a month, and $4800 a year. By comparison, Daisy Bacon, in her own writings, disclosed that she made $12,000 a year throughout the Depression.