Google Analytics, why doesn't it track very well? Maybe because you need to place a link on your site page and hope that your site doesn't go out. Or maybe hope that nothing goes wrong with the link Google provides. There's a lot of reason's why Google Analytics doesn't work so well. Just because Google is so huge doesn't mean they offer great services. Google Analytics is a free service, so how much time and money do you think they really put into it. There is no real support for it from Google, just a forum they setup for other users to help each out. When you visit the forum you will see that more people are looking for help or reporting a problem related to tracking than any other thing - http://www.google.com/support/forum/p/Google+Analytics/label?lid=55b995552f657452&hl=en. The problem isn't our traffic, the problem is that people rely on Google so much that they can never be wrong.
How is traffic delivered? When someone loads an url in their browser that's in our system their directed to one of our traffic servers url, then directed to a campaign listed within that server. All campaigns are assigned their own url code to receive the traffic within the server. Larger campaigns receive traffic faster to remain equally with smaller ones. We try to finish all campaigns within 90 days, which we do.