Why does OpenX's stats not match the statistics of another program?

You might find that the statistics within OpenX might not match the statistics you see when counting your websites' page impressions or the statistics listed in a 3rd party application for a banner that you are displaying within OpenX as a 3rd party banner.

There are many variables involved in comparing statistics:

1) Are you viewing the same Time Period of statistics in both softwares?

2) Does one software not count certain impressions or clicks due to different rules? For instance, in one software a click might not be counted if it comes from the same session or IP as another recent click.

3) If you are placing a 3rd party ad tag inside OpenX, it might take longer for the 3rd party to record an impression or click. When a user views your website with an OpenX tag on it, OpenX counts an impression when a banner has been chosen and returned to them. If the banner is a 3rd party ad tag, it may then take additional time for the 3rd party to choose a banner, deliver it, and count an impression. OpenX has no way of knowing when this '2nd impression' actually occurs, because it relies on 3rd party scripts. The same can be said for a click.

4) If you are comparing banner impressions versus page impressions, this number can have many variables which will change the results. As with #3, a page impression script might load faster or slower than the OpenX banner impressions. Also, you may have more more than 1 banner on each page or no banners on some pages. Some page impression scripts, like awstats, might let you look at impressions everytime a certain file is called, rather than everytime a page is loaded: So OpenX' ajs.php would be counted to load 4x as normal if you have 4 banners on each page, and not all of those 4 loads would result in a banner impression. Don't confuse a file impression with a page impression.

5) Ad Blocking software: Such software is quite popular, but won't necessarily block OpenX' ad tags. In OpenX, the banners server from your chosen domain rather than a common domain which is known as an ad network, hence your domain won't be listed as disallowed by common Ad Blocking software. You are also are able to customize OpenX and the delivery file names, making it again less likely that the banners might be blocked. However, if you are delivering a 3rd party banner it is quite common that the 3rd party's domain or ad tag will be known by the Ad Blocking software. Hence, OpenX will count an impression but will not be able to tell that the 3rd party was unable to count an impression, similar to #3.

6) You might use the 3rd party ad tags in OpenX, but also outside of OpenX. If you are seeing more impressions and clicks in a 3rd party statistics page than within OpenX, it may be due to the fact that you, or someone else, uses the 3rd party ad tag outside of OpenX.

7) You may have not properly setup the 3rd party ad tag to track impressions and clicks.

These factors can be known to add up to about a 10-15% difference. The difference will vary greatly depending on items like your user audience, website server, and the 3rd party software. However, most cases will see less than 10% difference and in general will find the statistics to be extremely similar. OpenX has been successfully audited for statistical accuracy. If you are finding a difference above 10-15%, please consult this list carefully to rule out all possibilities. You may find that the difference is largely due to one of the items on the list.