The cost of Google Ads depends on the specific campaign and budget that an advertiser sets. Advertisers can choose to pay on a pay-per-click (PPC) basis, where they only pay when a user clicks on their ad, or on a cost-per-impression (CPM) basis, where they pay based on the number of times their ad is displayed. The cost-per-click and cost-per-impression rates vary depending on the competition for the specific keywords or websites that an advertiser is targeting.