The impressions metric is one of the most commonly cited metrics, mainly because most display ad inventory is bought and sold by impressions. It indicates how many times your advert has been seen, and prices are usually quoted in CPM, or cost per thousand impressions. Often, the more people that see your ad, the better. The reach is another common metric, and is calculated as the percentage of your target customers who see the ad, against the total targeted population. Reach goes along with frequency, which is the number of times each targeted consumer saw the ad. Some people feel that this metric is significant because of the "rule of seven", in that people must see an advert seven times before they buy, (Dennis Payne, 2011).
The clicks metric is also one of the most relevant metrics. Combine this with the impressions metric to work out the CTR (Click Through Rate). The CTR is the percentage of people who click on the ad. CTR's for banner ads tend to run around 0.9%, and there has been much discussion over whether clicks are even a good metric for whether an ad is achieving its goal. Another metric that is now starting to supplant CTR with display ads is the view-through, which links site traffic with earlier impression, often using floodlight tags to make the connection between impressions and visits.
Conversions are what happen when a person clicks on your ad and then goes through a desired action. This may be filling out a form or making a sale. The desired action must be noted with the advertising platform so that they can monitor it. When these actions happen they are called conversions. The conversion rate is then figured out through people who converted and people who did not. This makes the conversion rate. The higher the conversion rate, the better.
These are some of the most significant metrics for display advertising. For further discussion of planning and running effective display ad campaigns, go to the Vantage Local blog.
Dennis Payne, 2011 - business insider, Editor-in-Chief of CityRoom.com, President of the MBMA marketing agency.
George Rawlinson, 1966 - Aesop's Fables, 620BC, The Histories of Herodotus of Halicarnassus. trans. George Rawlinson, Book I, p.132
Worldwidewebsize, 2012 - Web Statistics