It's call market segmentation. A seller want to sell their good to every buyer at exactly the highest price that buyer is willing to pay. The seller can't do t

It's call market segmentation. A seller want to sell their good to every buyer at exactly the highest price that buyer is willing to pay. The seller can't do that if they give everyone the same price so they look for ways to segment the buyers into groups which have similar valuations and charge each group a different price. If you pay attention, most pricing schemes are about market segmentation. Region locked items is obviously one. Most digital goods are sold at prices that decrease over time: it's basically segmenting the market by time. Buyers with high valuations buy first, those with lower valuations buy later, etc.