Google analytics has updated there tracking system in April 2011. There has been an issue with Google analytics that started back in April and was said to be resolved. The timeline and description appears to match what we have experienced over the last month and a half, and  we are not sure if there are still lingering affects that has caused problems with tracking. You can read more about this on the following article.   http://analytics.blogspot.com/2011/05/issue-affecting-analytics-data-for.html   In order for an ad campaign to be tracked in Google Analytics, advertising links to your website must have tracking parameters appended to them. The GATC code then uses a combination of page URL and referral parameters to identify the campaign being sent. This information is then is stored in the visitor cookie for your site and sent in the utmcc parameter of the GIF request. In many cases, website URL redirects will strip either the tracking parameters or the referral data from these links, and this leads to incorrect campaign reports.

We have been looking into resolving current issues with Google Analytics. Based on a couple of tests it is our opinion that Google is no longer showing 301 and 302 redirects as traffic. This is not a problem if you are mailing an ad that goes directly to a landing page. Unfortunately most marketing companies must track a clients campaign on their end so they can provide statistics and analysis for a particular campaign.  To do this a tracking link is automatically generated within the mailing software. When an end-user clicks on a link within an ad they will first go to the tracking link and from there be redirected to the "clients landing page".  We will be working directly with Google to see if there could be any other problems. We are not sure how long it may take to resolve this issue, however we can provide a temporary solution. In addition to sending our clients tracking reports from our own tracking system (that illustrates opens, clicks etc), we will also be sending our clients a tracking login pertaining to a third party tracking system that will track redirects. This message not only goes out to our clients that have been seeing our traffic on GA for years, we would also like to shed some light on the situation with new clients. 

SOLUTIONS

We have ran countless tests over the past few weeks. From these results, we can say our system can be detectable on Google Analytics. When comparing our test campaign setup versus other campaigns that are experiencing issues, there are two notable differences:
1. Some campaigns are not placing the Google Analytic code within the header section before the </head> tag as instructed on Google Analytics.
2. The code being used is outdated compared the most recent one that I used for testing.

There is a possibility then in this case that the updated Google Analytic code has changes that require its use for better tracking on page views. This will require you to make sure that you have the latest version of Google analytics.

We wanted to choose an independent tracking system that was free and extremely popular. Based on the popularity ranking of Bit.ly we decided that this would be our third party independent tracking system. Presently Bit.ly is  holding a spot with Google in the top 100 US websites (rated #99). You can view the popularity of this site at the following link. http://www.alexa.com/topsites/countries;3/US .

We will send you a login information (user name and password) prior to any broadcast so you can follow the campaign on a daily basis.

Other key notes about the Google analytic changes.

Our techs have spent countless hours uncovering  how GA split the traffic and conversions between different sources. They have learned that it works through cookies and that the basic cookie for source tracking is _utmz. However, the source data stored in _utmz is not always updated. It depends on the source. Theoretically, it is updated each time with the correct source data when people arrives to your site . However If someone writes your URL into the browser or goes to it from a bookmark or an untagged link in an e-mail it will only be written as direct in the _utmz cookie if the cookie does not exist or has expired (it expiries in 6 months!). The _utmz cookie is set once per visit (session) where each session expires after 30 minutes of inactivity, or when you close the browser. The only exception is if the source is "direct" and the visitor already has a utmz cookie, as "direct" will never overwrite another source, but any other source (organic, etc) will. All that means is that if someone finds your website in a Google natural result and clicks, _utmz value will be set to "organic" from Google. If the user likes your website and bookmarks it or uses it as starting page on the browser and starts visiting your site weekly and making some conversions, all his visits and conversions will be assigned to Google Organic sources because direct traffic does NOT update source value in _utmz cookie.

More trouble shooting http://code.google.com/apis/analytics/docs/tracking/gaTrackingTroubleshooting.html

http://www.prestashop.com/forums/viewthread/98368/configuring___using_prestashop/why_wont_my_google_analytics_work