Even though the marketplace platforms take many security measures, it's difficult to completely prevent the occurrences of illegally obtained keys from dishonest sellers. Instead, they are a hub for 3rd party sellers - similarly to Amazon. Marketplace Marketplaces unlike other stores, don't usually sell stock on their own. Payment fee will be added on top of the price displayed in store when you reach the checkout.The source of the key is unknown - it may come from a boxed version of the game or from another digital store. The key does not come directly from the publisher.