I’m not sure what could explain the discrepancy. I checked your site, and the tracking code is there and works properly. I do not see any caching plugins that may cause problems either.
I ran a few tests and all my visits were logged. You can check by checking your referrer summary for today, and look for 4 entries with 4 different keywords starting with site:
Could you try to install another tracking service like Google Analytics, with a plugin like this one:
http://wordpress.org/extend/plugins/google-analytics-for-wordpress/
The plugin allows you to exclude your own visits as well, as you could recreate a tracking environment similar to Jetpack, and see if the stats match the Jetpack reports.
Thanks for checking it out. Yes, I’m seeing your four views in my stats panel. Very curious… I’ll try installing Google Analytics and see how the numbers match up between Jetpack and my logs.
Google Analytics is up and running and collecting data. I’ll wait a few days and see what happens.
Meanwhile, I examined how Jetpack gathers statistics and noticed the following: When a user who isn’t logged into WordPress.com visits a blog that uses Jetpack statistics, the generated HTML contains a call to a JavaScript stats tracker that’s loaded from the WordPress.com server.
Now if I’m correct this means Jetpack won’t track any views by visitors who are (a) not logged into WordPress.com and (b) use either NoScript or any form of ad blocker that blocks remote script execution. Moreover, Jetpack also won’t see any views from China which blocks WordPress.com altogether.
Googe Analytics also uses remotely loaded JavaScript so it should produce stats fairly close to Jetpack, but it will also miss anyone who isn’t logged into WordPress.com and blocks remote script execution. (Voluntarily or not, in the case of China!)
When a user who isn’t logged into WordPress.com visits a blog that uses Jetpack statistics, the generated HTML contains a call to a JavaScript stats tracker that’s loaded from the WordPress.com server.
This tracking code will appear to all visitors, whether they’re logged in to a WordPress.com account or not. It won’t appear for users that are currently logged in to your site though. If you want registered users to be recorded too, you can change this setting by clicking on “Configure” under the Stats module in the Jetpack menu.
Now if I’m correct this means Jetpack won’t track any views by visitors who are (a) not logged into WordPress.com and (b) use either NoScript or any form of ad blocker that blocks remote script execution. Moreover, Jetpack also won’t see any views from China which blocks WordPress.com altogether.
As I mentioned above, WordPress.com users will be tracked, but you’re correct about (b) and (c) (China). If you block Javascript, your visit won’t be recorded. But as you mentioned, that’s the case for most tracking solutions out there.
All right, thanks for the clarification.
Something else occurred to me, aside from outright XSS blocking. Privacy tools like DoNotTrackMe and Ghostery are fairly popular, and both advertise selective blocking of services such as Google Analytics and WordPress Stats. Widespread use of such tools seems the most plausible explanation at this point, especially given my rather technical audience.
I’ll keep watching Google Analytics for a bit; so far it seems to match Jetpack stats. If nothing else comes up I’ll write a follow-up post and put those missed views down to (global or selective) blocking of cross-site scripting. Thanks for your time!
