If you have a website which includes some sore of lead generation such as a catalog request or newsletter subscription Google analytics can help track your success.
Any goal action can be traced back to the original source of the visitor. You can track exactly where your visitors came from and exactly where they are going. The Google analytics goal setting feature is especially useful when targeting keywords in your S.E.O efforts. Knowing ahead of time what keywords are already converting for your site and targeting those keywords until you reach the top organic positions as a very effective S.E.O strategy.
Get your account today for free at http://www.google.com/analytics.
Just create a account and ad the code to your html after your head code.