Friday night is often a place where television shows go to die, and on the major networks, science fiction tends to be especially prominent there.
Consider FOX, which is notorious for airing new shows which win an enthusiastic following, then pulling the plug on them – like Dark Angel, Firefly, Terminator: The Sarah Connor Chronicles, and Dollhouse, all of which came to their ends in the notorious death slot (and in cases, began there).
Indeed, Friday night is now especially crowded with such shows, so that shows of roughly the same type are running head to head in the same slots: Chuck and Nikita, both of which are McG-produced spy-fi, air at 8 PM on NBC and the CW respectively. Grimm and Supernatural (both of which are dark tales of investigators of the supernatural) run against each other right afterward on the same channels, while FOX airs Fringe (another story of investigators looking into the paranormal) in the same time slot.
Ironically, the fact that similar shows are competing so closely for the same, limited viewing audience makes it more difficult for them to survive, but then these are the shows the networks have nearly written off, and indeed, which are of kinds especially prone to being written off.
Chuck does not have far to fall at this point (it is not just in this trouble slot, but already in its last season), but the other shows mentioned here would seem to be on shaky ground – and it is a fair bet that most of the newer shows about which industry-watchers are more optimistic will follow them there before long.
New and Noteworthy (SFTV Ratings, Movie Grosses, Bond 23)
The Return of Chuck