The promotion is sponsored by Potawatomi Bingo Casino (Milwaukee, WI). So, I imagine they are doing it for marketing. They are also games during the week so the attendance would be lower than a weekend game, I assume. Though from listening to the Brewers on MLB.com radio, it seems like they are having strong attendance.
Works out great for me because one of the things on the "to do" while visiting my home state is to catch a game or two.
My Want List:
Repro WGSH Alter Ego Peter Parker, Dick Grayson & Clark Kent
WGSH Invisible Girl, Isis, Wondergirl & Aqualad (loose)
1970s Hulk or Spider-man metal garbage can
Comic book original art
Marvel Universe 3 3/4" figures (loose)
Have lots of comics and Marvel Legends figures for trades. Thanks!