Sellermania’s Prestashop marketplaces module exports your product feed to the Sellermania feed manager, which in turn is responsible for distributing your products on the various marketplaces and updating stocks.
From Sellermania’s feed manager, you then define all kinds of filters and rules that allow you to optimize your flow. For example, you can decide not to put on marketplaces products with less than x units in stock.
You can also exclude a particular product, range, supplier, brand, etc., that you wish to reserve for your site and not export to marketplaces.
The update frequency is configurable, many sellers schedule it for 8x per day.