I can’t stress enough that, if you are running online marketing campaigns, you have to track them for measuring success. There is no excuse for any online marketer to not track their campaigns through either paid or free analytic software. Google Analytics (/www.google.com/analytics) is a free software that enables any marketer to see how well their Search campaign is going, as well as, other online campaigns. What’s great about this software is that you can place a simple tracking code, provided by Google Analytics, on your website to see how specific campaigns are converting at your site, how users are interacting with the site, and if you have an e-commerce site, how well sales are converting. Without knowing how new users and repeat users are interacting with your site, you won’t be able to know how to improve the user experience to increase registrant or sales conversions.
There is a down-side to Google Analytics, it has problems aggregating all of the traffic accurately for unique visitors and visits. For example, if you are running a Facebook advertising campaign, Google statistically will show less traffic to your site, than what Facebook reports, but hey, what do you expect from a free software.
For a more robust analytic software, try WebTrends. WebTrends can be customized to your needs and is very granular about its tracking. Keeping in mind, it is a paid software, but if you can afford it, I would highly recommend it. If you are running a Search campaign, you’ll be able to see, down to the keyword, if new registrants or sales can be accounted to those specific keywords.