Abstract: Example methods and systems are directed to generating recommendations based on one or more user inventories, which may be stored in a database. The inventory may include items (e.g., physical goods, electronic goods, and financial assets) owned by a user. A machine may use the database to provide suggestions to the user to buy or sell items. The machine may also use the database to provide suggestions to the user to join a community. The database may be used in conjunction with an electronic commerce site. The machine may be aware of which items in the site are being viewed by the user. The recommendation made by the machine may take into account the item being viewed. The user may be able to view the current market value for each item individually, the total value for a selection of items, or the total value for all items.