Would new games bought online help the developer?

If i bought a game new from Amazon.com or the Amazon.com marketplace, Or if i bought a game new from Ebay, will the money still go to the developer as it would if i bought a game new from gamestop?

Every copy of the game paid the developer. If you buy a new game then you bought it from a retailer which acquired the game from a distributor that bought it from a publisher whom pays the developer.