Maybe because the Walmart buyer didn't think it was important to stock it. Around the time the original Battlestar Galactica hit DVD, I was in a local Walmart looking for that set and something else. Too many years have passed and I can't remember the other TV series title, but a employee standing in the DVD section asked me if I needed help. I told her what I was looking for and she said they didn't have it. Her reply: "I'm the buyer for this store, and I had never heard of that TV show so I didn't order any". she went on to say "I've made a mistake with that one, you are the 2nd person today that have asked about it" I hate to think over the years badly selling titles sold that way just because buyers at stores didn't recognize the TV series name.