Impressions
An impression occurs when your site is served an ad and the user is able to view it. So, for example, if one user is able to see three Chitika ads on your page, you will receive 3 impressions.
Another example – say that you have 100 users visit your page on a given day, but only 80 of them are visiting from a country that can see Chitika ads. This would result in 80 impressions.
eCPM
For beginners, eCPM can be a confusing stat. It is simply a way to track ad performance – it means “effective cost per mile (thousand impressions).” In simpler terms, it is the amount you are paid per 1,000 impressions. This is also very helpful when comparing channel performance.
Let’s say that on one channel you received 550 impressions and received $1.25 in total revenue. The other channel received 125 impressions and $0.55 in revenue. To compare the channels, you would use eCPM. The first channel’s eCPM is $2.27, and the second’s is $4.40. So, even though you earned more with the first channel, the second one actually performed better comparatively.
Revenue
As a publisher, isn’t this the point of having ads on your page? Therefore, I’m sure you all know what this stat mean$. 
all kinds of support questions on a daily basis here at Chitika. Today he was gracious enough to share 3 important questions that ALL types of Chitika users could benefit from.
What’s the difference between an “impression” and a “page view”?
“You may see these two terms used often and different contexts. While they have similar meanings, it’s the context that makes the difference. Page views are a measure of website traffic. In this context, the term page view represents every time a page from your site is requested by a visitor. If you have three visitors that each request five pages, this will result in fifteen page views for your site.
Impressions are a measurement of the number of ads that are shown on your site. An impression occurs any time an ad unit is displayed. If you have two Chitika ad units on your page and five users request the page, the result will be ten ad impressions since the five users each saw two ad units.”
Are “unique IP addresses” the same as “unique visitors”?
“An IP address is a basically just a numeric pointer for computers and servers on the internet to be able to find each other. For example, if you type “www.Chitika.com” into your web browser, your computer and our servers know how to talk to each other based on this numerical IP address. Therefore, when you look at the number of unique IP addresses accessing your web site, what that loosely means is the number of different machines requesting information from your site.
The area where these two terms are blurred is when either a user accesses your site from multiple machines on separate IP address – for example, at work and at home. In this case, the number of users and IP addresses are both two, but there is actually only one unique visitor. On the other hand, a home or business could have a network that uses only one IP address on the internet. In this case, if two people from inside the network access your site, the unique IP address count would only be one, but the unique visitor count should be two. Generally, web statistics are reported in unique visitors, though this number is a highly-refined estimate.”
breakdown of impressions, clicks, CTR, Avg CPC and eCPM
“As explained previously, an impression is counted anytime an ad is displayed to your visitor. This may happen multiple times per page view if there are multiple ad units on a page. A click is a fairly easy unit of measurement – a click occurs when your user clicks on your ad. CTR or click-through-rate is the percentage of your impressions that garner clicks. For example, if your site has 1,000 impressions in a day and results in 10 clicks, you would have a 1% CTR.
Average CPC or cost-per-click is the average amount that you are paid per click generated from the ad units on your site. This number is represented as an average of the CPCs that you get on each click for each day. Specific CPC values can fluctuate depending on the market and having the average of these values helps to illustrate the overall trends of the CPCs generated for your ads.
eCPM or effective cost-per-thousand impressions (the M is for the roman numeral M meaning 1,000) is a unit designed to help normalize the performance of a CPC ad unit. On a simple level, this number represents the amount revenue you would generate for 1,000 impressions based on your current CTR and CPC. As an example, if you had 1,000 impressions at a 2% CTR you would generate 20 clicks. If your average CPC was $0.20 for those clicks, you’d earn $4 on those 1,000 impressions – a $4.00 eCPM.”
