The abbreviation CRR stands for Cost Revenue Ratio and represents the percentage ratio between expenses and actual sales. It is used in Google Ads and Microsoft Advertising. CRR is employed when the maximum advertising costs are known. A lower CRR indicates a more cost-effective and profitable advertising campaign. Conversely, a higher CRR signifies a larger proportion of costs in relation to revenue. For instance, if the CRR is 25%, it means that the costs account for one-fourth of the revenue.