Not necessarily. It took a season or 6 of NCIS to get a NCIS Los Angeles. If the current series maintain success, I wouldn't be surprised to see another spin-off of CSI, but only not at this point.
It took six seasons of NCIS for it to have a spin-off maybe because it wasn't so popular before. It premiered in 2003. In 2004-2005, some of today's popular shows like Lost, Desperate Housewives, Grey's Anatomy, House and CSI: NY have premiered. Somehow, NCIS was kind of forgotten. But now, NCIS is a ratings juggernaut and so popular and having a spin-off is a proof. If CSI is going to have a spin-off in the future, I want it to be in Chicago or Seattle. I hope CSI is still on-air by that time. I want it to last the longest among the three.
I will watch for sure but I am not sure it will work.It looks like CSI is struggling. London would be perfect becouse it will be different.
I don't think a fourth CSI would be a good idea. If it was set in another country, like the aforementioned ideas of London and Australia, it would be a bit different, but even then, I don't think it would be a good idea.
Thing is, things are become more and more about the same. A change in approach might make difference. An option could be more character focused. Another option is closing a huge file once in four or five episodes.
Based on this qualtative vote. It's better not to spin-off a new series. However, I do believe that there's a high demand in guest locations. Like: CSI - Los Angeles. CSI Miami - Rio de Janeiro and Los Angeles. CSI NY - Chicago and Greece. Who knows there'll be more guest locations available in the upcoming seasons.