They don't, because unlike Ubisoft, they're mostly a middleman. They run the marketplace for other game vendors and so they have reputation to uphold. However,

They don't, because unlike Ubisoft, they're mostly a middleman. They run the marketplace for other game vendors and so they have reputation to uphold. However, Ubisoft is primarily a game developer, so there is a moral hazard of them screwing you. We all hate middlemen but this shows why they're needed (in the absence of regulation).