I worked the gun counter at Cabela's in Acworth when I was in college at KSU.At Bass Pro/Cabelas, when they ask if I want to sign up for their credit card, I just say "Sorry, I'm poor" and the awkwardly shut up and avoid eye contact. It's great.
For their chance to win promotions, I just say "Sorry. I don't gamble anymore" and they drop it. Make it as awkward as possible and they won't push it.
They ABSOLUTELY antagonize employees to push those stupid club cards on customers...
It was my most hated part of working there.
For each credit card signup an employee gets, the employee gets one whole dollar added to their paycheck.
I never tried to get people to sign up for that crap because I hate being asked to sign up for it 35 times whenever I'm in one of those stores.
I try to be nice about saying "no," but I completely understand why people lose their patience with being bugged about it while in there.