No "Value per Visit" if I use campaigns


I have set a goal in piwik and added this to the script

piwikTracker.trackGoal(1, 15.90);

Piwik tracks the goal and also the value (15,90) as overall revenue.

If I use also a campaign and a keyword, both is tracked by piwik.
But if I have a look in to the campaings section I see no value for "Value per Visit"
The conversionsrate is correct, but no value there.

Here the complete Javascript:

<!-- Piwik -->
<script type="text/javascript">
var pkBaseURL = (("https:" == document.location.protocol) ? "" : ""winking smiley;
document.write(unescape("%3Cscript src='" + pkBaseURL + "piwik.js' type='text/javascript'%3E%3C/script%3E"winking smiley);
<script type="text/javascript">
try {
	var piwikTracker = Piwik.getTracker(pkBaseURL + "piwik.php", 3);
        piwikTracker.trackGoal(1, 15.90);
} catch( err ) {}
</script><noscript><p><img src="" style="border:0" alt=""/></p></noscript>
<!-- End Piwik Tag -->