This guest post is by Beeri Amiel, Head of Business Development at Sigmento and an expert on Amazon ASINs.

Amazon standard identification numbers are not as standardized as they should be.

In many cases, there can be multiple Amazon ASINs for the exact same product. This leads to duplicate listings, sellers having difficulty reaching potential clients, and frustrated customers.

As an Amazon seller, you need to ensure that the ASINs you use are the “right” ASINs and appropriate for each country. That's because different countries may have different Amazon ASINs for the same product.

If you're concerned that you're using incorrect ASINs, read on to learn how to choose the best ones.

When sellers use the wrong Amazon ASINs

Using the wrong ASIN or multiple ASINs for the same product can result in listings that don’t show up in Amazon search results. Worse, duplicate listings will confuse and frustrate your customers, potentially leading Amazon to block you from selling.

Duplicate listings often occur when multiple GTINs or MPNs are used to identify products which Amazon categorizes under a single ASIN.

Manufacturers often assign different GTINs to the same product based on the sales channel it will be distributed on (I.E. retail store, online. etc.), since products are often customized for each channel.

Amazon cares about the products the customer actually receives. So, to Amazon, a pair of headphones sold in a blister pack would be considered the exact same product as the headphones sold in box, while a marketer could have identified these using different GTINs.

Warning signs that an Amazon ASIN is bad

There are several warning signs that an ASIN is “bad” for your specific product.

If any of the following attributes are not an exact match to your product, this should be a warning sign to review your ASINs:

• Size

• Color

•Category

• Weight

• Title

• Dimensions 

• Quantity

While this may seem self-explanatory, there are many instances in which the differences are easy to miss.

For example, a seller might have a single item comprised of 4 pieces, while the ASIN often lists the product as a “4-pack” item. A shopper would be expecting to receive 4 pieces of the same product, while the actual product is a single item.

How product categories factor into the Amazon ASIN equation

Another important aspect of identifying the best ASIN is the product’s category on Amazon.  

A seller might have his product in the category “clothing and accessories,” while the ASIN he uses is associated with “baby clothes.”

This might not seem like such a big deal, especially if the product is actually for babies.

But, one category may have a higher chance of people searching for it, and if you list your product in the less-popular category, it could cost you visibility and conversions.

How Amazon sellers can select the best ASINs

Researching ASINs involves a manual process of checking different product attributes. While it sounds easy, there's often still confusion or uncertainty about what the differences are between ASINs after research.

In selecting the best ASIN, product attributes to consider are:

• product title

• brand name

• package configuration, and

• price

Multiple ASINs may be a good fit based on the above attributes. But, you should also consider the elements below:

• sales rank

• search rank

• parent child options (where relevant), and

• reviews

Combining these criteria should narrow down the possible ASINs enough for you to choose the best one. 

Potential pitfalls in researching and picking ASINs

Researching products in this fashion is not always a practical way to ensure you use the best Amazon ASIN for your product.

Choosing the best ASIN may not be such a challenging task for up to a handful of products.

But, this can be a tedious and time-consuming process for sellers with even the smallest of catalogs (under 50 products).

Although ASINs may seem accurate, they can and often do change as Amazon strives to provide a better shopping experience.

Amazon constantly scans and reviews GTINs and MPNs, and as product information changes (such as color, weight or size) Amazon will change the ASIN accordingly (and notify any sellers using the “old” ASIN).

To avoid losing sales due to issues with Amazon and ASINs, it is imperative that sellers maintain accurate and up-to-date ASINs on all of their products.

To facilitate this, retailers should demand that distributors and/or manufacturers provide them with accurate GTINs and MPNs that match their Amazon inventory.

This will help ensure that the ASINs (which are based on GTIN and MPN data) you use are correct, enabling a better shopping experience for you potential customers.

Beeri Amiel is the Head of Business Development at Sigmento, which provides optimized product information on demand. Sigmento’s platform allows retailers to find product identifiers such as ASIN, UPC, Brand & MPN for their entire catalog. Sigmento also offers this feature as a Magento extension on Magento Connect. For more information go to sigmento.com/product-identifiers