Welcome to the Q&A Forum

While the exact definition of "stronger" generally falls on pure authority and strength, it is skewing more to perceived user intent.  What I mean by this is that if Google infers that the user is looking to purchase a product they would be more prone to rank Amazon however if they believe the user is simply looking for product information they would rank the Samsung site. I a lot of generic queries it's difficult for Google to determine, at least early in the search cycle where they may not have a pre-defined idea of what you're trying to do.  In that case they would have to lean on pure strength.  That said, as they're getting better and better at personalization of results, one could conclude (and I personally do) that if they see you searching phone models and generally clicking on online stores, that they would then infer that even on the next model-specific generic search, that you'd prefer a shopping experience delivered over the Samsung site and it's product based information.