My guesses...let's assume all the merchants paid about 1 cent per mile to 'sponsor' their placement. If I remember the game correctly, you got about 5 merchant offers as you went through the board, thus every 10K winner could be sponsored 2,000 miles or so. At a cost of 1cent/mile, that is roughly $20 per player - no way any merchant would offer up that kind of marketing spend without a clear return on investment. Let's say a mistake was made and the game was for 1,000 miles: the cost would be $2 per player - still a BIG price to pay to sponsor an unlimited pool of players.

From Delta's perspective, the game, which I still consider ingenious, was a chance to reinforce their message through active participation by a customer (or potential customer) - which is excellent marketing. Perhaps they figured on collecting a flat placement fee from the sponsors and then just fronted the remaining "cost" of the miles (not everyone got the full 10K it seems) on the books as part of the marketing budget to offset the liability of all these extra miles being issued.

Or....this game was the winning marketing submission by one of The Apprentice players and its creation will be seen on an upcoming episode.

As far as a devaluation - even if they dont raise redemption levels (I doubt they will), everyone suffered a kind of devaluation today. Issuing a free additional supply of miles to all takers will increase everyone's balances (not just Elites and FTers), and grant an easy opportunity for occassional flyers to begin redeeming against those previously sub-25K accounts, increasing demand for, and competition for limited award seats. 10,000 miles is ALOT to just give away - if someone had collected 20,000 miles over a few years, played the game today and then applied for a DL Amex card, they now have a free domestic FC award or almost two free coach awards.