Cost of sales / cost of revenues is in general a huge problem, and there's a long history of benefits accruing to businesses which work out how to bypass that.
Magazine subscriptions (bundling), utility services (a novel concept in the late 19th century), governments (taxes), banks, etc.
It's why the enterprise market is far more appealing, generally: make a few large-ticket enterprise sales (mostly to the F-10 - F-500), even if they do take forever to land, and roll in the recurring revenues.
Retail sales is far more about the distribution deals than the register sales (the second follows the first). Competition is generally over the marketing channel and/or real estate (look up "dark grocery stores" for more on that last).
Or as I'd realised the first time I heard Milt F. rattle on about TANSTAFL, there's no such thing as a free lunch revenue-capture system either.