Think about it though. The kids sang the song a couple times to practice and once during the program. My daughter's class sang Take Me Out To The Ballgame last year for the Spring Sing and it's not like all the kids have turned into baseball fanatics. My daughter hasn't even asked me to go to a game this year and I always watch baseball. I don't see any kids in the street playing baseball.
On the other hand, my daughter knows damn near every billboard on I-65. She sees a McDonald's billboard and instantly asks for a McNugget meal even though she knows the answer will be no.
Now you tell me whether a billboard or a song has a bigger impact. Give me some anecdotal evidence or statistics unless you want to join the rest of the group that just gets all shitty when someone says something you don't agree with...
You forgot one important thing: baseball is ing lame.
Okay, two important things: McDonald's is ing everywhere. You can't reduce it down to just one billboard. They're ubiquitous.
EDIT: To clarify, no, I don't think that singing this song is gonna turn little Timmy and Susy into Obamunauts. "Brainwashing" is overrated. I just consider it ing weird and creepy, yeah?