Reading example: In ‘Month 0’ we took over the bidding for Google Shopping advertisements. In month 3 the Sales Index was at 307, up from 100 in Month 0. This represents a sales increase of 207%. In that same month the index for Cost of Sales was at 40, representing an advertising cost decrease of 60%.
‘Sales’ is defined as the revenue (or: Conversion Value) resulting from Shopping advertisements as registered by Google.
‘Advertising Cost of Sales’ (ACoS) is defined as: advertising expenses divided by the corresponding ‘Sales’. E.g. if a retailer spends €20,- on advertising to generate €100,- in Sales, then the ACoS is 20%.