CSI and For awhile, investing so heavily in these franchises made sense for CBS. NCIS was and continues to be one of the most-watched series on American television. Last year, in its 17th season, NCIS accounted for 10 of the 100 most-watched US TV broadcasts of the year. On average, its episodes were each seen by 10.5 million viewers—a huge number in this era of cord-cutting and streaming dominance. CSI was also immensely popular, regularly bringing in more than 20 million viewers per episode in its heyday in the mid-2000s. It stood to reason that spinoffs of both of these franchises would perform similarly well.