What's behind Cassini and the default sort order
“Cassini” is the common name for eBay's search engine. The default sort order is called “Best Match”. According to eBay, it takes several factors into account, including relevance to the search query.
What buyers see also depends on sponsored listings, the filters they set, and a sort order they choose themselves.
What eBay itself recommends
In its help pages, eBay advises starting with competitive prices, reasonable shipping costs, and good customer service, and creating complete, accurate listings.
eBay doesn't publish the exact formula and weighting. So read claims like “factor X brings Y percent more visibility” with caution.
Where listing data helps in concrete terms
Item specifics: Buyers filter by brand, size, or color. If the detail is missing, your listing may be missing from filtered results.
Product identifiers: Brand, EAN/GTIN, and manufacturer part number assign your listing to a product in a structured way. Which details are needed depends on the category.
Shipping costs: Buyers compare the total price of item price plus shipping. Outdated amounts make your listing needlessly expensive or cost you margin.
Be careful with guarantees and insider tips
No tool and no agency can guarantee a position in eBay search. That includes eOptima.
Many tips come from individual observations or old sources. Search changes constantly; what applied earlier may no longer be true today.
How to proceed in practice
Start with the details you can verify with certainty: item specifics, manufacturer part numbers, and shipping costs. In eOptima, quick filters and review mode show where such details are missing or deviate from your rate.
Don't change anything just because a tip recommends it. Every detail has to match the product; incorrect item specifics help neither you nor your buyers.
As of October 2026. eBay features may change; the information in eBay Help is authoritative. eBay is a trademark of eBay Inc.; eOptima is an independent service.