Cluster has the most comprehensive product data catalog in the market, tracking eCommerce sales of over 50,000+ categories across Amazon, Walmart and eBay in real time. This accounts for over 80% of business that is conducted online today. We also have the largest structured SKU-level dataset available with over 1B items with full product level attributes (SKU, UPC, EAN, ASIN, GTIN, Color, Dimensions, etc.). That being said, if a product does not contain a GTIN, Cluster also has the ability to lookup products by keywords to identify and even recommend a GTIN for an item.