Posted on Facebook yesterday.
What if you could put a dialog-based spoiler alert on a post.
You wouldn't be able to read the comments until you confirm that you know there are spoilers below, and be given a chance to know what the spoilers relate to.
Or -- even better -- I could say the post is only visible to people who have declared in their prefs that they've already seen the season finale of Game of Thrones season 5.
Think of all the new metadata you'll get.
Of course if HBO NOW had community features, it would be killer there, because they would know that you've already seen the episode, without the user doing anything. Or Amazon or Netflix, for their shows.