We spent today coming back to Michigan from my in-laws in Tennessee. That's a pretty good chunk of the Bible Belt we traversed, and a common roadside sight was some sort of eschatological prodding for folks to come to Jesus-"Jesus is coming, are you ready?" is the prototype of such messages, often accompanied by a just-before-midnight clock reminding me of the cold-war Doomsday Clock.
I'm not sure if that's great theology, for it seems to cast Him as some sort of blood-thirsty alien that will devour anyone who can't flash a Get-Out-of-Hell-Free card. Disaster preppers will have their multi-month stash of food and water and plenty of firepower to fight off the zombies and Mad Maxes of the secular end-times, while rapture preppers will have their salvation stashed as well; post-tribbers might well have both.
Jesus is more than just a get-out-of-hell-free pass. He's Lord and Savior, and the fear-merchants seem to miss the first part, not to mention the ongoing help of the Holy Spirit. Discipleship, walking with the Lord, seems to be well off-screen in that milieu.
That's not to say that the folks posting those turn-or-burn type signs don't do a good job of ministering to people beyond saying the Sinner's Prayer (or some such confession) and making a trip to the dunk tank, but that can be the metrics of choice in many circles.
I will admit that those scary signs are better evangelism than none at all; to borrow from Moody, their way of evangelizing is better than my way of not evangelizing (not much beyond the blog, at least). I'd just want to see something beyond a punch-card salvation in people's lives.