After seeing Apple and the NFL using Hayne for Game Pass promotion I had an idea.
If you purchase Game Pass within the app, am I correct in thinking that it will bill your iTunes account?
If that's the case, in the absence of any promo codes, could you use iTunes vouchers (that you'd bought at 20% off) to pay for it, saving 20% that way?
Can you even use multiple iTunes vouchers at once? (ie. on the one purchase? I'm usually too lazy for vouchers, iTunes is just linked to my CC)