Great question — answering as the UphillTech team:
We have a similar issue with trying to collapse products from multiple merchant feeds. What we do is collapse products based on their brand (or manufacturer) + sku combo. Our data is pretty messy so we have to do some work to normalize both the brand and the sku so the products collapse nicely. We have a list of brands that we care about and do some work to map brands from the merchant feed into our brand. e.g. If we have an "ACME" brand in our system we might map the following to that brand: A.C.M.E => ACME ACME Inc. => ACME Acme Incorporated => ACME For skus we usually just strip any non-alphanumeric characters for matching purposes. e.g. all the following would map to the same sku:...
Full answer by tpunder: https://stackoverflow.stackexchange.com/a/2564062 (CC BY-SA 2.5).
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