The series' newfound success led to the idea

After the original series was cancelled, Paramount Studios, who had bought the series from Desilu, licensed the broadcast syndication rights to help recoup the production losses. Reruns began in the fall of 1969 and by the late 1970s the series aired in over 150 domestic and 60 international markets. This helped Star Trek develop a cult following greater than its popularity during its original run.[15]

One sign of the series' growing popularity was the first Star Trek convention which occurred on January 21–23, 1972 in New York City. Although the original estimate of attendees was only a few hundred, several thousand fans turned up. Star Trek fans continue to attend similar conventions worldwide.[16]

The series' newfound success led to the idea of reviving the franchise.[17] Filmation with Paramount Television produced the first post original series show, Star Trek: The Animated Series. It ran on NBC for twenty-two half-hour episodes over two seasons on Saturday mornings from 1973 to 1974. Although short lived, typical for animated productions in that timeslot during that period, the series garnered the franchise's only "Best Series" Emmy Award as opposed to the franchise's later technical ones. Paramount Pictures and Roddenberry began developing a new series, Star Trek: Phase II, in May 1975 in response to the franchise's newfound popularity. However, work on the series ended when the proposed Paramount Television Service folded.