That UI Guy on Dairy Queen gift card use: You have to click a button when presented with one choice
0If a user ever has one choice to pick and it is not a confirmation point, just take that choice. Do not waste the user's time. Do not confuse them why there is just one button or have the cashier explain to click it.
Bonus industry specific second part analysis:
Also, have you guys thought about letting automatically check gift cards by swiping or would you be concerned at the security of people using swipe POS card readers without an employee watching. This is a problem across all franchises/corporate stores it seems. I actually ate at Dairy Queen instead of Subway because at Subway the new employees could not figure out how to tell me my gift card balance. If security issues are not a thing, people should be able to swipe their gift card at the same card reader they sell at.
I understand though maybe why they do not do this... If it is more difficult to use a gift card, more people will keep them unused and thus the company has more effective money/interest accruing. Again this second part is an industry issue, not anything specific to Dairy Queen.