Decoding the World’s Largest E-commerce Search Engine: Amazon’s A9 Algorithm
https://moz.com/blog/amazon-vs-google
Amazon, with 54 percent of product searches taking place, is the world’s largest search engine for e-commerce. Technically, Amazon is the second largest search engine in the world excluding Google.
Compared with Google, Amazon asks very different questions to deliver the right results to the user: “What product is the searcher most likely to buy?” Amazon’s search engine serves one purpose—to understand searches just enough to rank products based on their propensity to sell.
The system Amazon uses to decide how products are ranked in search results is called A9 Algorithm. Because Amazon is a business, the A9 algorithm puts a strong emphasis on sales conversions. A technical term is “Sales Velocity”, which is essentially the speed and volume at which your products sell on Amazon’s marketplace. There are lots of factors which Amazon SEO’s refer to as “direct” and “indirect” ranking factors, but ultimately every single one of them ties back to sales velocity in some way. For the same reason, Amazon’s core ranking pillars are tied back to driving revenue through sales velocity — Conversion Rate, Keyword Relevance and of course, Customer Satisfaction.
Conversion rates have a direct impact on the rank of a product. A relatively low price, a good-looking product listing and a well-written title and product description can all contribute to the conversions. Another unique point about Amazon SEO is that a good performance on marketing channel can boost ranking. This is because if a product is selling through ads, Amazon’s algorithm may see this as a product that users should also see organically. Keyword matching, another core pillar of Amazon SEO, is designed to determine the relevance of a product to searcher’s query. The last pillar is the customer satisfaction, driven by part of Amazon’s mission “to be the Earth’s most customer-centric company”. Customer reviews are one of the most important Amazon ranking factors. Reviews help to drive both conversion rate and keyword relevance, particularly for long-tail terms.
Keyword Relevance can be thought of as a similar determinant as what we have learned on page rank. The key takeaway from Amazon’s SEO is that all the core pillars are designed to serve the business. The algorithm built on the calculation of sales velocity is the secret to its success.