. . . . "CPA advertising" . "Cost per wear" . "Cost per action (CPA)" . . "Cost_per_action" . "CPA" . "Cost per action/acquisition" . "effective cost" . "Cost per action" . "cost-per-action" . "Cost per acquisition" . "cost per action" . "per inquiry advertisements" . . "Cost per action" . . "effective cost per action" . "CPA (cost-per-action)" .