Always leave'm Wantin' More
If Star Trek (TOS) hadn't been canceled, would it have been such a success in syndication? Would there have been such a hankering for 4 series to follow and 11(?) movies. Had the need for Star Trek been fulfilled in the 60/70's perhaps we'd be so tired of it, there might not have been a market for follow-on series.

The following was posted on Jokeaday.com
Star Trek (TV) (1966)
The transporter was a plot device intended to eliminate the pacing and production problems involved in depicting the ship landing and taking off all the time.

Shortly after the cancellation of the series, the staff of the marketing department of the NBC TV network confronted the network executives and berated them for canceling Star Trek, the most profitable show on the network in terms of demographic profiling of the ratings. They explained that although the show was never higher than #52 in the general ratings, its audience profile had the largest concentration of viewers of ages 16 to 39, the most sought after television audience for advertisers to reach. In other words, the show, despite the low ratings, had the precise audience advertisers hungered for, which was more than ample justification to consider the show a big success.