Five Star Commerce is a US-based agency that offers “on-demand consulting for Amazon”—handling services for physical-product brands who want to sell on Amazon and other 3rd-party marketplaces. They help with everything from account setup and listing optimization to advertising, PPC campaigns, graphics, and overall account management. Their model is hourly-based (no long-term lock-in or monthly minimums), letting clients scale the support up or down as needed.