When you dig into the details, you'll find some pretty interesting things most people never notice. As I was cataloging out my missing issues from Uncle Larry's Action Comics, I found just such an oddity. The math of issues by year just didn't add up. After scrolling through each issue I finally stumbled upon the fact that in 1973, there were only 11 issues. Specifically the issue for May 1973 was missing. What happened? Was there a specialty issue that took place that month instead? Did DC run out of paper in the end of April?
As I was browsing through Wikipedia for an unrelated reason, I stumbled upon the answer. In the page on Cover Dates I found this footnote (it seems this comment has moved its way onto the Action Comics page since then, but it was more fun finding it somewhere unexpected):
Levitz, Paul (2010). 75 Years of DC Comics The Art of Modern Mythmaking. Taschen America. p. 516. ISBN 978-3-8365-1981-6. "Cover dates on comics didn't match magazine dating norms, and by 1973 Marvel's cover dates made them appear newer than DC's, so DC decided to skip using May 1973 and go straight to June."
So there you have it, DC skipped a month as a marketing ploy. That's almost as cheesy as the time the Craftsman® Bolt-On™ System Saved the Justice League!
It hearkens back to the ol' one-page comic advertisements where a superhero would save the world with a Hostess® Fruit Pie or something.
The Flash saves the day! Although it looks like I spilled some Fruit Pie on the corner of the page.