"Mark my words" traditionally means that you should get some credit for being "right about something.
In this case, there's no real mystery, just some people who have to know what is going to happen on a fictional show BEFORE it happens so they can brag about it, and the rest of us who love to SPECULATE on what would happen since we have kept ourselves pure from actual KNOWLEDGE.
Those who want to be kept in the dark and speculate will not think you better simply because you went and read stuff about the show.
The people ON the show know what is going to happen before you do. We don't think they are special either.
If you don't like what I say, don't read it. I make a point never to say anything except generic comments such as my favorite prediction, "Jack is going to say 'd*mnit!' during the show" or "it will be exciting". Those who want to know more, I discuss it with them via e-mail. I would never ruin the show on purpose.
Now perhaps we can all stop slinging cyber mud and get back to the topic.
Now if you'll excuse me, I've got some work to do. I'll be back on around 6:00 Central.