You know my background is marketing and this has to be one of the best to add customers to a site I have ever seen, not just to share but to share a URL reaching many people each time it is shared. What did a case of 223 cost them? nothing to manage, just let it grow on its own.
Now your assignment is to do the same for LSB. A prize, use the same setup they do, not sharing the forum but the the contest, that way it can be posted everywhere and no one will get their panties in a wad for advertising a competing forum. I would say night vision, but to really get this spread, ammo, what ammo? 22LR(seems to be the most desired and hardest to get), how much? a case? how and what will it cost? very little, each of os donate and ship to TLM a brick, all different kinds, whatever you have, 300-500 bricks, it does not matter. He counts it and takes a pic of all stacked in a pyramid tower and puts the rd count at the bottom...what 5000, 10,000 15,000? And that picture is the centerpiece of the add for the contest. So the entire promotion costs each of us the cost of a brick and the forum shipping to the winner (maybe the business sponsors could share this). I am in for a brick.
Anyway just 1 idea of a prize, work it out, agree to it, set it up and LSB do its own contest. Once each of us share it to a couple other forums it will take on a life of its own. I would give it longer than this contest is running for.