For an ad entering into an auction on the Google Display Network, the AdWords system will calculate the effective cost-per-thousand impressions (eCPM) when there are:

Question

Accepted Answer

any cost-per-click (CPC) or cost-per-acquisition (CPA) ads entering the auction

Answer

both cost-per-click (CPC) and cost-per-acquisition (CPA) ads entering the auction

Answer

only cost-per-click (CPC) ads entering the auction

Answer

only cost-per-thousand impressions (CPM) ads entering the auction