You're right, Berned. Overall, it's a good and great thing - to remind people of the ultimate 2nd coming of Christ - especially for those who have forgotten the wonderful meaning and essence of the first coming.
I gather from your previous posts that you are eager to play the teacher and can be dismissive of others who do not share your theological views so I will simply state that while we have some disagreements over scriptural meanings, the Left Behind books, while not destructive, are somewhat misleading - but as you say, if they get the unsaved to at least consider the future and eventually go to scripture and even come to the Lord, that's fine. I don't really endorse them but I wouldn't stop someone from reading them, either, however I would certainly urge an unsaved 'fan' of the books to then go to scripture for the true story.
The problem is that the new Christian is totally unprepared to deal with Revelation and other deep scriptures. They need milk before they are ready for meat. When you take the unsaved or the simply curious into scriptural areas that even lifelong Christians with years of study still contend over the result is often confusion and eventually, a rejection of the whole Bible as 'a story'. I've seen this happen.
The 'Left Behind' series has merit and I'm glad it's well received but I still highly recommend the Bible, God's Word to his creation, first, before trusting secular ficton using the Bible as a vehicle to bring the unsaved to Christ.