Product feeds put your website's inventory in front of shoppers on Google (free Shopping listings via Merchant Center) and Facebook & Instagram (a shop gallery on your pages). In both cases the buyer completes the purchase on your website — the feed is a discovery channel, not another marketplace.
Where the feeds live
Both feeds are generated from the Export Data page (Inventory section), under Third-party feeds. Each feed has a setup guide linked right beside it that walks through the platform side — creating a Google Merchant Center account or a Meta shop, and pointing it at your feed.
Automatic updates
Rather than uploading a file by hand, turn on scheduled feeds from the feed's setup guide: BookRouter publishes your feed at a private address that Google or Meta fetches on its own schedule. Your listings stay current as inventory changes, and for Google it also sidesteps the 30-day listing expiry that manual uploads suffer.
Controlling what is included
Feeds include your website-visible inventory. To keep specific items out, use the exclude-SKUs option on the feed's export panel.
Good company for this article: Setting up Google Analytics and Google Tag Manager, so you can see the traffic and sales these channels bring in.