OpenX Tips

Newcomers to OpenX often ask a seemingly simple question: “Why don’t I have the same number of impression in OpenX as page views in my website stats program?”

As is often the case, the answer is never quite as simple as the question, and you may need to look in a few different places before reaching the “aha!” moment where all becomes clear.

Number of ads per page

The most obvious starting point in the page views vs. OpenX impressions conundrum is to check how many ads you have per page on your site. If you have more than one ad per page, then you should have more OpenX impression than page views. If you have some pages without any ads, then you should have less OpenX impression than page views.

Of course, if you have some pages with one or more ads, and some without, or pages with varying numbers of ads per page, then obviously, you’ll need to do a little bit of maths to figure out your expected ratio of OpenX impressions to page views!

This might all seem pretty obvious, but it’s still worth noting, as it’s often overlooked.

Drop off

In the event that you have consistently less impression in OpenX than you were expecting relative to your number of page views, then drop off could be the culprit. Drop off occurs when a user clicks on a link in your page content, clicks the back button on the browser, or maybe even goes to a completely different page or even site before the ads on the page have loaded from OpenX and had their impressions recorded.

Now, some level of drop off is normal, and to be expected. You will never be able to eliminate drop off entirely, so please don’t waste your time trying!

However, if you are suffering from a high level of drop off — that is, very many less ad impressions than you were expecting — then there are three main possible reasons for this:

• Poor site load performance can lead to drop off, as users don’t wait for the entire page to load before navigating to another page. For this reason, it is important that you measure your site performance;
• Very large banner sizes and slow 3rd party tags can be a cause of ads loading slowly, which may obviously result in ads not fully loading by the time users go to another page; and
• The location of your ads on the page¹ or the use of end page placement & positioning with CSS can also result in drop off.

You can look at the difference in requests vs. impression in OpenX to help you diagnose drop off issues.

Web log analyzer issues

Web log analyzers look at web server logs to generate the number of page impressions on your site. If you are using a web log analyzer, and you are seeing a ratio of OpenX impression to page views that don’t make sense, then the following are all worth investigating:

• Check that your web log analyzer is working properly — is it processing all your log files? Is your web server logging everything that it should be?;
• Is your web log analyzer correctly excluding items from your web server log that are not page impressions? That is, are all calls to images, CSS files, JavaScript files, etc. being correctly excluded from page view counts? Most web log analyzers should do this by default, but it is worth double-checking; and
• Finally, have you set up your web log analyzer to exclude all of the calls to the OpenX scripts from being analyzed?

1. Ads placed at the bottom of the page are more likely to result in drop off. [↩]