CPM – Cost Per Thousand view. Even if banners are booked by the week you will need to understand the total number of impressions that are likely and the distribution of these impressions over the days of the week and over the hours of the day. Without this it is difficult to accurately predict the effectiveness of the campaign in real time.
CTR – Click Through Rate. What % of people actually clicks on an ad. This is used to access the popularity of a particular creative or placement.
CPC – Cost Per Click. How much each click cost you.
CR – Conversion Rate. What percentage of clicks/visitors took the desired action of the campaign (business outcome)
CPA – Cost Per Action. How much did each action (business outcome cost)
CPO – Cost Per Order. In e-commerce situations the cost per order is a vial measurement.
ROI – Return on Investment. For every dollar you spent how much profit you made. Often this is less than 1 in the case of new customer acquisition.
LTV – Life Time Value. For every dollar spent on customer acquisition and servicing how much profit did you make each period (week/month/year). At the break even point this is equal to 1 and should increase above this as repeat business is generated.