CPC, or cost-per-click, is a digital marketing metric that measures the amount of money an advertiser pays each time a user clicks on their online advertisement. This form of payment is commonly used in pay-per-click (PPC) advertising, where advertisers bid on keywords and pay for each click their ad receives. CPC is a crucial factor in determining the success of a PPC campaign, as it directly affects the return on investment (ROI) for the advertiser. A lower CPC indicates a more efficient and cost-effective campaign, while a higher CPC may require adjustments to the ad targeting or bidding strategy. Overall, CPC is a key metric for businesses looking to drive traffic and conversions through online advertising.