Click the links to find out!  In short, it is a currency created by Let's Talk Bitcoin, a podcast run by Adam Levine which is long-running and successful (i.e., it has sponsors, i.e. people or companies who pay to have their advertisements placed in the podcasts).  People who contribute content to the podcast (on-air talent, behind the scenes/production members, etc.), and to the LetsTalkBitcoin ecosystem in general (forum members, etc.), are rewarded with LTBCoin for their contributions.  Let's Talk Bitcoin sponsors will be limited to ONLY being able to purchase advertising with LTBCoin.  In this way, a market is created for purchasers of LTBCoin.

E.g. let's say that an ad on the podcast costs 1000 LTBCoin.  Prior to the creation of LTBCoin, the cost for an ad on the podcast cost $500.  Somebody wanting to place an ad on the podcast will now have to purchase 1000 LTBCoin on the open market (which is basically the Counterparty DEX, although other exchanges could pick it up as well).  This creates a rough value of $0.50 per LTBCoin.

New LTBCoins will be distributed for several years, although after that distribution period, all coins will have been distributed and the LTBCoin economy will rely on recycled coins (sponsors send coins to Let's Talk Bitcoin to pay for ads, and Let's Talk Bitcoin distributes those coins to contributors).  Since LTBCoin lives entirely on Counterparty, there is no mining and essentially no cost to the LTBCoin creators or holders.  (Other than BTC transaction fees, of course.)

I believe that this is a fantastic idea, and that it could well see widespread adoption throughout the digital media universe.  Basically any site which has: A) Contributors and B) Advertisers can create their own coin and follow this model.