How can i fill shelves with products so that I have the maximum amount of sales?
You'd need to give an exact specification of the problem, but we can do something. It sounds that every item can in principle be placed anywhere, but has a different value depending on where it is placed. It's not quite clear how "value" and "max sales possibility" interact, that's for you to figure out. 

I'd try to find a "profit" per item, which will depend on its shelf location. What's even more important is "profit per meter". Since the profit changes by the same percentage for all items, you want to put all items with "high profit per meter" to positions where their profit isn't removed. 

A "greedy" algorithm would start by sorting all items by profit per meter. Then you put the items sorted by profit per meter into the high-value places first. That gives you a decent solution. 

You will have unused space left, so you will try to improve things by putting items there that fit better. Say you had a meter high value space and put a 60cm item there and don't have anything to use the leftover 40cm, then maybe placing a 100cm item would be better. That's reasonably similar to bin packing. 

You can be pretty sure that the problem is NP-complete, which means in layman's terms that neither you nor anyone else will be able to find an optimal solution in reasonable time, so you try to find a good solution instead.