Cost-per-thousand impressions (CPM): Definition, A way to bid where you pay per one thousand views (impressions) on the Google Display Network. If you'd like to pay only for ad impressions measured as viewable, you can with viewable CPM (cost-per-thousand impressions). CPM stands for "cost per 1000 impressions. With a vCPM ad, the max viewable CPM bid represents how much the advertiser is willing to pay for each 1,000 viewable impressions; with a CPC ad, Google. In Q1 2018, advertisers spent, on average, $2. Google Search Ads Benchmarks - Q1 2018.