Last week, like most other channels on the remote, CBS went to “holiday special” mood. Sweep out some of the shows, they figured, and plug in the stuff that you'll only see once in a while—last week, for instance, they aired a television movie on someone suffering from Tourette's syndrome and proving himself to the world. Which means, it's an interruption of your regular programming. So, you most probably had to contend with a repeat of The Unit a day earlier than expected.
Yeah, it can work well sometimes. Of course, some people might not be able to catch the episode when it originally aired; to add to the mess they probably were sleepy enough to forget to set the DVR to record the entire thing, football overruns and all, and end up with no way of catching up. Or, you might feel like watching it again—either you want a second look (I'm guilty of that), or you'll probably go, “ahh, I don't want football and I don't want cop chases, so I'll just watch this then.” It still draws some eyeballs, and networks love eyeballs. It does serve its purpose, after all.