Ali (and others?) offer a discount for an "app" and scanning a code -- what benefit there?

Olso, out of curiousity — I don’t have a “smartphone” so I don’t have an “app” to buy at a discount.

I see that now at AliExpress, maybe others.

Does everyone see the same little graphics “code” box or is each person served a unique one?

How much is the discount, and what does the “app” provide to the seller or to Ali?

does it identify the user, track interest, target future advertising, etc.?

I assume since the user is being given a discount for buying with an “app” that the seller or Ali get something for that money. What?

watch out!
some of those apps have been found to contain malware!