Microsoft Marketplace is Microsoft's online store for software made by other companies: cloud solutions, SaaS (software sold as a subscription), AI apps and agents, and add-ins for Office and Microsoft 365. An Office add-in is a small web application that runs inside an Office program such as Word, Excel or Outlook and adds features to it. Business customers search the store, start trials and buy.
A publisher creates a company developer account in Partner Center, which goes through an approval process, and then submits the solution. Each submission passes automated checks against Microsoft's certification policies and a review by a validation team, which can take 3 to 5 working days. An add-in listed in the Marketplace also appears in the add-in store inside Office. Offers can be free, BYOL (the customer brings a license bought elsewhere), or transactable: Microsoft sells the license for the publisher and bills the customer's Microsoft subscription or credit card, with pricing models such as flat rate, per user or usage-based.
On transactable offers Microsoft keeps a store service fee, a percentage of each sale.