Shortly after the cancellation of the series due to low ratings, the staff of the marketing department of NBC confronted the network executives and berated them for canceling this show, which had been one of their most profitable series without anyone realizing it. They explained that although the show was never higher than number fifty-two in the general ratings, when running the numbers though the replacement of the Nielsen rating system, its audience profile had the largest concentration of viewers of ages 18 to 45. In other words, not only did the show have the most sought-after demographic that television advertisers hunger for, it was also one of the most successful series the network had ever aired, and did even better in reruns. This was more than ample justification to contact Gene Roddenberry with a request to revitalize the show. Unfortunately, this turned out impossible, as Paramount had just cleared out their warehouses of most of the sets and props, and rebuilding them would cost around $750,000, so instead, the studio greenlit Star Trek: The Animated Series (1973). Although Roddenberry wasn't really interested in doing an animated show, he agreed, in the hope that the show would be successful enough to revive the original series (which it unfortunately didn't).
Leonard Nimoy recounted to The A.V. Club in July 2010: "the gesture that I introduced into 'Star Trek,' the split-fingered Vulcan salute, we'll call it... that came from an experience - I'm going all the way back to my childhood again - when I was about eight years old, sitting in the synagogue at high holiday services with my family. There comes a moment in the ceremony when the congregation is blessed by a group of gentlemen known as Kohanim, members of the priestly tribe of the Hebrews. And the blessing is one that we see in the Old and New Testament: "May the Lord bless you and keep you; may the Lord cause His countenance to shine upon you," and so forth. When they give this blessing, you're told not to look! You're supposed to avert your eyes. I peeked, and I saw these guys with their hands stretched out-there were five or six of them, all with their hands stretched out toward the congregation-in that gesture, that split-fingered gesture. Sometime later, I learned that the shape that hand creates is a letter in the Hebrew alphabet, the letter shin, which is the first letter in the word Shaddai, which is the name of the Almighty. So, the suggestion is that they're using a symbol of God's name with their hands as they bless the congregation."
When NBC was promoting Star Trek in magazines, all shots of Spock's pointed eyebrows and ears were airbrushed out of the pictures because NBC thought that no one would watch the show due to Spock's resemblance to the Devil. However, this concern was quickly invalidated upon the series' airing with Spock becoming not only one of the most popular characters, but also a sex symbol with young female viewers, an audience reaction no one in the cast or crew anticipated. Spock's resemblance to the devil is subtly hinted at at the end of Catspaw (1967)(#2.7) when McCoy & Kirk say "I wonder if there are any demons on board this ship" while looking at Spock.
Leonard Nimoy's father was a barber, who was still operating a barbershop at the time the series became popular. In a mid-1960s interview with 16 Magazine, Nimoy revealed that youngsters often came into the shop asking for a "Mr. Spock" haircut, never realizing that "Mr. Spock's dad" was cutting their hair.
The series was originally produced at Desilu Studios, which was owned by Lucille Ball. Ball heavily advocated for the show, and it was largely her influence with NBC which lead to a second chance after rejection of the original pilot. Ball was also said to be a genuine fan of the show, and often is affectionally referred to as Star Trek's Godmother.