I’m not convinced it’s that good because of how the deals are structured. For example, top deal where I am at the moment is 9 chicken nuggets plus two medium drinks plus two sauces for 1990 HUF. That’s a two person deal (you don’t need two drinks if you’re on your own), but there are no chips, add a large chips to share at 1270 HUF and your meal costs 3260 HUF. Two four nugget McMoment deals comes to 3060 HUF (small fries, small drink). Are an extra 80ml of coke and half a nugget each worth 200 HUF? Maybe? But it’s definitely not the huge savings it purports to be.

This walkthrough is just an example, open the app yourself and have a look, most of the deals are just an item or two away from being a thing people would actually order.

I’d rather pay full price than sell McDonalds my data, I’ll never notice paying 25% more given how little I eat there.

If everyone else refused to sell their data, we wouldn’t be in this position.

Of course! That is why I qualified it as "averaged over all menu items". The expectation is that higher-margin items are purchased in a volume that balances out lower-margin items.

Also sodas/fountain drinks are famously high-margin. Depending on the size, as much as a third of the COGS comes from the disposable cup.