It wasn't too long ago that This Is The End was going to be drowned out among much better movies. Who knew a comedy made in part so the actors could hang out while filming would actually be successful, especially since they were all playing themselves (albeit for comedic effect). It went up against a new Superman movie. It was poised to fail or at least break even and fade into the back of a busy summer season. Even with the deck stacked against it, This Is The End did very good for itself. Nearing the $100 million mark the film finally left theaters with something accomplished that much more marketed films, The Lone Ranger for instance, couldn't reach.
Despite doing pretty well for itself This Is The End isn't ready to go away and in fact will be coming to a theater near you. Now that theaters have calmed down and we don't have big budget films releasing every Thursday it would be a good chance for a movie like this to come out. Or at least that's what Sony and Columbia pictures hope for with re-release of this movie. According to them moviegoers really enjoyed this film and are bringing it back for those who didn't get a chance to see it. Also if you would give them more money they would really love that.
I don't entirely see the reasoning of this choice unless theaters just so happen to still have the original reels of the movie. If you could just redistribute a movie, have minimal marketing, all at a much smaller cost and using the profits the movie already made then why not? While this smacks as money grabbing you can't be mad at a studio taking advantage of the current lull at the box office.