From the Sept. 13, 1978, edition of Variety


“Laverne & Shirley”, starring Penny Marshall and Cindy Williams, was a mainstay of ABC’s lineup from 1976 to 1983.

This ad is notable for its focus on the show’s performance with distinct demographic groups — aka the “key demos” that would come to drive primetime TV ad sales for decades to come.

https://variety.com/gallery/tv-ads-rare-variety-star-trek-freaks-and-geeks-sopranos-dawsons-creek-west-wing/deewallace/