digital marketplace, Steam platform, transaction fee, percentage cut, virtual goods, in-game items, skins, trading cards, community market, user-to-user transactions, Valve Corporation, revenue share, economic model, online gaming, microtransactions, digital economy, Steam wallet, financial policy, gaming community, service charge, marketplace dynamics, virtual economy, digital distribution, Steam sales, gamer spending, platform maintenance, infrastructure costs, monetization strategy, user base, Steam client, gaming industry, transaction system, digital storefront, profit margin, user agreement, Steam terms of service.