Sorry I was not aware of GAAP. Anyways, I think the primary benefit is the interest-free financing. The company gets to hold the customer's cash and use it for operations (working capital) for the entire time the gift card is unspent. Maybe I was not right with the account terminology and should have mentioned the cash flow positive impact only.

Maybe it is more accurate this way?

It's a combination of things: marketing (difficult to quantify, but > 0), interest/appreciation on the float (4-10% annually), forecasted overspend (30-40%), and breakage (5-10%).

The GC face value is a liability on the books though. It's treated as debt when doing cash calculations.

They actually do want you to use the cards though. The overspend is more valuable to them than the other disposition possibilities. Recognized revenue is always the best outcome. The interest/appreciation is the same for the merchant, whether on float or on revenue, but revenue is better for reports.

More broadly: All benefits of the cards definitely accrue to the merchant. There's absolutely nothing valuable to consumers about the deal!