Referrer tracking: Differences Omniture, Piwik, Google Analytics


My latest project was featured on a design showcase gallery.

That showcase gallery uses two ways to link to my website:

1.The URL shortener
2. A direkt link pointing directly

The URL shortener - - preserves the referrer so it does not show up in my Piwik stats.
But: I am also tracking with Google Analytics and Omniture. While Omniture does not show the real referrer, Google Analytics recognises the referrer:

Visits from a certain showcase gallery:

Omniture: 143*
Piwik: 131*
Google Analytics: 1 494**

*Probably visitors using the direct link.
** Visitors using the direct link +

Why does Google Analytics know the referrer? Is there a way to make Piwik also realize the real referrer?

Are you sure you tagged all pages, with the google +piwik code? definitely piwik should detect the referrer like GA does.