In Poland, the major competitor to Amazon is Allegro (https://allegro.pl/). It's an online shopping platform that is not as centralised as Amazon. It's more of a marketplace where both small and larger sellers can list their items. In tandem with InPost (which has lockers spread around entire country), Allegro creates a great and efficient online shopping experience. The only drawback for me really is that sometimes if you order a numer of things, they will all come shipped separately.