The following factors will decide on which seller receives the Buybox:
Price: The lower the price, the higher the probability of obtaining the Buybox. This does not mean, though, that it is always necessarily the lowest priced offer which will be given the Buybox.
FBA / Prime: Offering a product with Prime fulfilment will increase the chances of obtaining the Buybox significantly. Alternatively sellers should be able to uphold an avarage delivery time of under 2 days.
Seller Rating: The more seller reviews and the better the seller rating is, the higher the chance of obtaining the Buybox.
Reaction Time: The faster sellers can react to to customer inquiries, the better for any Buybox aspirations. The avarage response time should be under 24 hours.
Frustration-Free Packaging (FFP): Getting FFP certified with Amazon, which entails reducing the general amount of packing material used, will also aid towards a higher Buybox percentage, more about this here.
The most important factors are the price and FBA. If a seller uses FBA and is offering the lowest price, the chances are very good of receiving the Buybox.
Please note: Sellers can only obtain a buybox after being listed on Amazon for at least 3 months.
More detailed information about winning the Buybox can be obtained in our Blog (click here).
Additonally, this blog article (click here) explains what is important to know about the buybox.