Cassini eBay search engine guide


Cassini is eBay’s internal search engine. Rolled out in 2013, Cassini has been programmed to gather data regarding human search, engagement, and purchasing behavior.

When a person visits eBay and searches for “running shoes” the eBay search engine tracks behavior including                           (but not limited to):

  • What is your return policy
  • What is your response time to customer questions
  • Do you have complete product info
  • Do you have quality pictures of your products
  • What is your feedback quality score
  • What are your shipping policies, prices, and delivery times
  • Do you have valuable and accurate product descriptions
  • What prices are you asking for products
  • At what price point are you starting bidding
  • What are your click-through and sell-through ratios

Based on the data gathered, Cassini is programmed assign scores to each listing based on how well a listing meets the customer’s search criteria and preferences based on their own previous behavior.

In the past, it was easy to cheat search engines (eBay’s included) by “stuffing” keywords all over the place. Search engines are now incredibly sophisticated and it’s pretty much impossible to fool them. Nobody outside of the programmers who create Cassini’s algorithm even knows exactly how it works.

What we do know is that eBay strives to create what they call “customer-centered commerce.” This means that they make the customers wants and needs the focus of all their decisions. Your goal as an eBay seller should be no different, and the Cassini search engine helps you achieve that goal.

The Cassini search engine is completely modeled around customer behavior. When a customer comes to eBay and types a keyword into the search box, eBay will show them every listing with that keyword in the title. This could be hundreds of thousands of listings, so the Cassini engine sorts them to try and show the most relevant results first.

Listings are “scored” based upon 4 key metrics:

  1. Item title
  2. Item specifics
  3. Category
  4. Catalogues

Each of these metrics has a whole host of best practices which must be followed to ensure that your product ranks well.

There is no golden rule for how to rank well with Cassini, but by understanding how it works, you can tailor listings to better meet Cassini’s requirements for a top result.

The first and most important thing to understand is that eBay wants to show customers results that are relevant to them, and that they will want to buy from. There is no point in showing laptops to someone who is only looking for a case. That said, eBay has studied buyer behavior and know that most customers want lots of results from a primary broad search, which they can then narrow down. Some customers will filter by adding keywords to their search, others will use the filters in the left-hand column. Either way, results will be determined by title and item specifics.

It is important to have full and correct category and item-specific information, as these really drive the filter engine in search results. Often, you may filter and see a list of brands, colors or sizes on the left-hand side, and then at the bottom will be ‘unspecified’. If you do not fill in item specifics, then your item will be in with the ‘unspecified’ and go unseen.

The importance of a good title

A good item title uses core product key words that describe the item.

Ebay gives you 80 characters to write your product title. Many people advise to try and fill these 80 characters with as many key words as possible. This is not always a good idea though, as Cassini bases your ranking not only on your listing, but also on how customers engage with it.

Every time a customer searches a key word which brings up your listing, Cassini counts this as an impression. Even if you are result twenty-two on a page where the customer only looks at the first two results, if you are on the page, it is counted as an impression. If the customer then adds another key word or uses the category filters, and your listing is a result again, that would be a second impression. The number of impressions your listing has is compared to the level of engagement your listing has, and this determines how relevant your listing is, and where it ranks.

If you pad out your item description with broader search terms, you increase exposure but dilute customer engagement, so damage your ranking.

One of the very best ways to find those specific keywords and keyword phrases that customers use to search for an item is to use the eBay keyword research tool –Terapeak.

Titles should be written for buyers. Writing in a smooth, readable way will get you a better engagement rate than a pile of keywords thrown together.

Qualifiers such as designer, material or color are helpful to a customer and search. But using other brand names with phrases such as “just like” breaches eBay rules and will result in your listings being taken down by eBay. Even if eBay did not remove them, this weakens customer engagement and so would damage your ranking.

Special characters are still sometimes seen in eBay titles. This outdated technique for catching customer attention only irritates modern customers and is seen by Cassini as a bad practice, so will not help your ranking at all.


Engagement is what Cassini values over everything else. It’s a broad term, but for Cassini it means how much time customers spend on your listings, and how many of them engage with is by watching or bidding. High buyer engagement will improve the ranking of your listings. There are many things which are proven to increase buyer engagement. Some key areas are:

    • High-quality photographs
    • Well written product description
    • Free delivery
    • Free returns

By creating listings that are more attractive to customers, you will increase the time customers spend looking at your listings, as well as how many choose to watch or bid. This in itself can only be a positive thing, but it will also increase the ranking of your listings.

The format of listings can also influence engagement. Single quantity fixed price presents one item to appeal to the millions of eBay customers. If you consolidate listings, incorporating multiple sizes and colors into one listing, you increase the amount of buyer engagement on that one listing.

Driving traffic from social media is one way to increase engagement on your listings. Froo apps smart social is a free app which allows you to automatically promote items on Facebook and Twitter, and keeps to set popular times to avoid spamming.

The bottom line

Cassini is a sophisticated search engine, designed to reward sellers who strive to answer the needs of their customers with integrity and an earnest desire to engage in transactions that are good for all parties involved. Honest and clear, informative listings, categorized correctly and supported with excellent customer service, will always rank well.