Mego, Jackson's creators, made a mistake in commissioning a line of television commercials for the doll to be produced by Mel Hellitzer Advertising. The commercials showed our 8" hero running, fighting, and otherwise cavorting in a series of stop-motion-animated adventures - which turned out to be against television industry rules. Toys at that time weren't allowed to be shown doing things in commercials that the product themselves couldn't do - child actors could be shown holding the toys and pretending they did various things, but tricks like animation and special effects were out. Taken aback, Mego continued to produce the action figure, but the line received a blow from which it never really recovered. Additional accessories, playsets, and even a female Jacksonian named Dinah-Mite were introduced, but by 1973 it was all over.
However, some good did come out of Jackson's failure. In an attempt to bounce back from the loss while at the same time cutting costs, Mego re-used the bodies of the AJ figures in a new line of figures to be launched in '73: the World's Greatest Superheroes. This toy line would reap the parent company millions over the next several years.