Cross-promoting is a powerful free tool to help you sell even more to buyers. When a buyer shows interest in one of your items (such as by placing a bid), four of your other items are promoted to the buyer in a display that shows other items you have currently listed.
Cross-promotions appear when:

A buyer bids on your item

A buyer wins your item

A buyer views your listing (for eBay Store sellers only)
To activate cross-promotions click the Change your Cross-Promotions link at the top of any of your current item pages or the Marketing Tools link in My eBay.
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