I'm curious as to how episodes of shows are selected for re-runs. I ask because I've noticed over the years of watching re-runs of various shows that they seem to favor certain episodes. I've noticed they usually don't re-run season/series premier/finales. Seems to be the same in both cartoon/animated series as well as live action shows.
One would assume it's based on popularity, but I'm not so sure about that. Do DVD sets play a role in re-run selections? Meaning they only show certain episodes in an attempt to increase sales? These are only speculations and guesses.
To @Crow T Robot's point, it does seem to matter if the show has a story line or not, but my wife has been watching Forensic Files since it first came out in 2000 and we have not seen a re-run of any episode in the first season (she records them all) in 5+ years but the same episode will get recorded on the DVR multiple times a week.
To @Sonny Burnett's point, I live in the US. Unless they are airing a marathon of a series, it's usually not in sequential order.