I went back and looked up two of CBS's most popular shows of the past, back when William Paley was President of CBS, which back in those days, CBS stood for the Columbia Broadcasting System. Anyhow, Gunsmoke is the only show that has had more seasons on CBS. It had a total of 20 Seasons, that is not including before TV and CBS was just a radio network before 1951, Gunsmoke was on the radio, to my understanding.
The Original Hawaii Five-O, with Jack Lord, ran from 1968 to 1980 and made it to 12 seasons.
Now, I see what is going on, and I am surpirsed that CSI-Vegas is getting another season, my only guess why is because of contract issues with the newest two characters that are now on that show.
Typically, as I stated before, most popular TV Shows only get 8-10 Seasons, at the most. I would have to look this up, but back in 1970, shows that Producer Paul Henning had on CBS like Green Acres, Petticoat Junction, and the Beverly Hillbillys (rural comedy shows) had good ratings, but in 1970, they pull all those rural comdey shows off and replaced them shows like "All in the Family". Thier reason was because of the racial tension in the late 60's, and CBS got pressure to start airing more Urban Oreinted shows.
This thing with ending the CSI Shows is nothing new, and they have done things like this in the past as I mentioned, but in today's world, we have this thing called "The Internet" that allows people to be more vocal to express thier views to corporations like CBS.
As I did some of this reasearch this evening, it appears that as big as CBS is, the biggest network, besides the BBC, they care more about revenue than ratings. Yes ratings are important to them, but when shows get 8 to 10 seasons like CSI NY and CSI Miami, they start looking for something "fresh" to hold viewers, give advertisers a new show to sell their products or services, and in addition, in today's world because the viewer has more choices, than we did 30-40 years ago, they are facing heavy competition.
In the end, my friends, we can complain, send emails to CBS, petitions, but it's not going to get us nowhere. Nancy Teller, President of CBS and the CBS Board is going to to what they think they should do to stay in business and keep that revenue coming in. They have been doing this for years, and I am beginning to believe the cast and behind the camera crews of all three CSI Shows knows the end is near, and it seems there is nothing they can do about it, but go find another job, or retire.
Peace