I'm sure it's real to some degree. Cause obviously the list isn't an all time list. It's a list that's only for some time recently. 1-2 weeks, a month, who knows. On top of that, they have a list that says what's recently been added to Netflix. I doubt maybe are doing research before picking out a movie that sounds interesting. And picking something that was just added is probably a pretty common choice since it means you probably haven't seen it on there before. I know it's what I do when looking for something new to watch and I don't have anything in mind already.
Also, what counts as watched? Watching for 5-15 minutes then turning it off? It would be a better list if it only counted those that completed the movie but it probably isn't, based on things I've heard about their stats before.