Unfortunately Apple's intention is that you would not hear about an alternative way to pay for the subscription and that the alternative way is cheaper.

I mean if you partnered with Target to sell your shampoo I think they would be rightfully pissed if the bottles you sent them to put down said something like "Buy it on our website instead for 30% cheaper!"

I imagine that if a consumer sees a product at Target, they have an idea that the product might be cheaper somewhere else. However, do consumers have an idea that if they seen an in-app purchase that the exact same thing might actually be on sale somewhere else and that it has a different price?

If the app says that "One year HEY subscription" is $142 and the app is from HEY itself, what reason is there to believe that it's not just the plain old price of HEY?

Harry's razors are sold at Target, and they do a subscription service for razor blades.