The tools to reach your analytic goals
There are a few different ways to collect analytics. There is script page tags, log file tracking, packet sniffers and api. There are benefits to each, and a good analytics package for an enterprise strategy often will employ more than one.
Script Page Tags are common, and include Google Analytics. They are very useful for capturing user driven data. They have more accurate session tracking, event tracking and can capture client side events. However, be careful, because any errors in the data capture are permanent. Also, the script might not load for all users, so if page views correlate with revenue, such as pay per impression, stay away from these analytics (or at least load the script in the head of the HTML page). There is also the problem of making sure all the pages have the proper script tag on them; large sites rarely achieve 100% page tagging accuracy. Some sites will be able to use 'mod_layout' to write the script to every requested page.
Log file tracking: In my earlier days, I loved throwing logs in the White River and watching them float on. As a professional I love watching log analytics accumulate. Log file tracking makes a data impression for everything. It counts partial page downloads that Script Page Tags don't get a chance to count because of the page not fully loading, or the user navigating away from the page. Also, Log File tracking allows you to see more errors and historical log files can be loaded, so you collect all the data. To pull a little SAT analogy Script Page Tags versus Log file tracking is like shooting photos in JPG versus Raw.
Packet Sniffers: If you look longingly at in depth segmentation reports, packet sniffers might be for you. Packet sniffers logs the communication that comes through your server, each request and response. You can collect an enormous amount of data, and determine exactly how each user is interacting with your site, even replay a user's click path.
API: If you subscribe to the thought that analytics is one of the most valuable business intelligence, and you want a competitive edge, a custom API is the path you need to pursue. Each business process is unique, and an off-the-self product might not fill all your needs. A custom API for your web application can better address the key performance indicators for your site, and help you gain a competitive edge in the marketplace.
The most important thing is to define the analytic goals before you invest resources in a solution.
