How does Adspert work for Google Shopping campaigns?

At Google Shopping campaigns there are product groups instead of keywords and placements. Adspert treats those product groups like keywords and placements. That means Adspert investigates clicks, impressions and conversions and sets CPC bids according that.
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Thereby, Adspert sets bids individually for every product group. That means the more product groups are created, the more specific can Adspert set bids.