I have never heard of this before, either (perhaps because I have been Platinum so long, they have never offered it to me).

This doesn't seem like a very good deal for a place like St. Louis, but, of course, everyone's valuation will vary, so I am glad that it works out for you.

I wonder if they place an upper bound on the number of offers they make to limit the number of people who have access to the lounge? Not a huge deal, but, theoretically, if everyone in the hotel took them up on this, then it would defeat the purpose of the lounge.

Perhaps a nice next step would be offering a $25 per night refund to Platinum members who promise not to use the lounge? That would be me much of the time.