Netflix "Watch Instantly" question

So my husband and I watch a lot of stuff via Netflix’s streaming service. Recently, we’ve been watching some of the older TV series that are available for viewing, but we’ve found that while entire series are available for viewing, it seems like every once in a while, there are specific episodes left out… you have to rent the actual DVD copy to see that specific episode. We were trying to figure out why that might be, and couldn’t really come up with anything. The best I could come up with was that they want you to have to rent the DVD because there’s advertising on it, but that seems a pretty thin argument.

Does anyone know why they leave (what appears to be) random episodes out?

I noticed this with Season 1 of Family Ties (which is surprisingly good!), and assumed it was done to make you feel you’re missing out and go buy the DVDs. But that doesn’t make any sense because you wouldn’t buy the DVD; you’d order it on Netflix.

Another idea is that licensing every episode for Watch Instantly is difficult somehow? Maybe to deter pirates from making complete copies of DVDs on their computers?

Perhaps its licensing issues regarding the music? I noticed this with American Gothic. Good thing Hulu has all of them.

I don’t think it’s licensing, though, and it doesn’t always appear to be random. For instance, I watched the first season of Little Britain, and apparently it contains 10 episodes. But you can only watch the first 8 with ‘Watch Instantly’, though you will get the full content if you put the disc in your queue for delivery. I don’t get that.

Maybe they just haven’t done whatever work is required to put up the remaining episodes? I assume they have to scan in the movies, or something like that.

Of course, if the episodes are still missing 2 or 3 months in the future, then that shoots my little theory down.

The string theory of Netflix.

Nobody really knows what the fuck is going on.