.... I'm starting to have my doubts about using the data from this site. I wonder if some of them are just made up for a store's inventory purposes.
I thought I'd start getting #s from exclusives, and was getting them for BotCon products, but where would they get such #s? There's no UPC # on the bags, and I found a box that FunPub had used for one souvenir set, that while it had a SKU #, it didn't have a UPC #. Unless it was a smaller box from within a larger box, and only the larger box had the UPC #. Although I'd be surprised it wasn't more widely used than that. Considering how amateurish their forum was, perhaps they didn't use UPC #s to track inventory and only did it manually.
I learned early on that the UPC database sites (there are many, also in EU) are only good for finding leads on items and cannot be used for confirmation. When documenting actual physical products, I also learn to not blindly accept what is listed on any other website without photo confirmation. The reasons for this is that some products use multiple UPC/EAN and can be mismatched on store websites.
But regarding these sites specifically, the UPC/EAN come from various sources:
1. The actual UPC/EAN if the item has it
2. A reseller/disty resell of old stock. Think of it when you see an item that has a label over the original UPC/EAN and has a new one printed on it.
3. Multi-packs (same as new label)
4. Import/export versions
5. Distribution cases
For 3-4 they can have the same similarities as #2. For #5, there are instances where a case will have a barcode on it while the products inside do not, have a different code, or have a label code.