In 1978 there were fewer outlets for stand-up comics on TV. Cable TV was used so that people in rural and isolated areas got broadcast channels -- very few people got "cable channels". On broadcast, variety shows were dying and the only shows for a stand-up comic to appear was the "Tonight Show with Johnny Carson", "Saturday Night Live" or one of the morning talk shows that were syndicated like Mike Douglas or Dinah Shore.
"The Comedy Shop" was a syndicated half-hour program to give more comics TV exposure. Hosted by Norm Crosby -- famous for his malapropisms -- he would introduce 5 or 6 comics each episode, and they would do a 3 minute bit on stage before a live audience. Once during each show you would hear someone knocking and Crosby would open a door behind him and reveal a special guest who was not a stand-up comic (e.g. Jill St. John, McLean Stevenson). The comics on the shows were not top tier, but "up and comers" who were getting much-needed TV exposure. Before commercial breaks the camera would zoom in on a celebrity in the audience who would do the "We'll be right back..."
This is a great sampling of stand-up comedy in this era, and limited to 3 minutes, most comics stuck to observational humor so the material doesn't seem too dated. It is frustrating sometimes, because after a particular bit you want to see more, but you don't know if that is possible 30 years later! I saw some of these shows at the time, and at this writing it is being shown on MyRetro-TV. Most of the comics are obscure today, though I remember a few of them. Many were introduced as opening a musical act -- a rite of passage for comics of those days.
Recommended for fans of stand-up comedy, for others a curious period piece. My rating is "9" mainly because of the format.
BTW, Brooks and Marsh's "Complete Directory of Prime-time Network and Cable TV Shows" (Ballentine Books, 1999) says there were 25 episodes released for syndication in the fall of 1978.