> A running gag throughout the Mel Brooks movie, "Spaceballs" is recurring product spots for the film's promotional materials

>From IMDB:

In a 2013 television interview (shorty before receiving the AFI Lifetime Achievement Award), Mel Brooks stated that he personally obtained George Lucas' full permission to parody any and all things Star Wars-related but, on one condition, that absolutely no merchandise of any kind be produced from the film. This is the reason why all Yogurt and the Dinks do is merchandising (it is also why none of the merchandise seen in the film was ever mass produced or publicly sold in any way).