Subscription ad for DC Comics back in 1972...
...notice the exception to the offer - 100 page super spectaculars for subscribers! Must have been painful for that year when Detective Comics was all 100 page super spectaculars editions (with the Manhunter stuff).
The newsstand vendor is completely out of DC Comics because he's been tearing off the covers, sending them back to the distributor for the return value, and selling the coverless remains to someone else for a little profit.
Why is that kid carrying around a pair of scissors? My theory: he's vandalizing the newsstands by cutting out the Marvel Value Stamps directly out of the comics there, leaving his own collection perfectly intact. This kid is a genius, a future Master of the Universe.