One huge error most merchants on the Internet make is that they fail to track some basic performance metrics to measure the financial performance of their websites. There are several key metrics that you should track.
These are:

• Conversion Rate- This is the percentage of visitors who convert into buyers. Conversion rates on the Internet average about 2%. The most efficient websites on the Internet consistently close at 2.5% to 3%. Conversion rates higher than that are unheard of.
• Average Order Size- This is the size of an average order in dollars. Some customers may spend more, some less, but on average, you should know your order size.
• Per-Click Budget- This is the key metric that will drive most of your efforts on the Internet. The per-click budget tells you how much a single visitor is worth to your website on average. This is measured in terms of dollars and cents.

These three metrics, which are easy to calculate and track are critical to your overall marketing efforts on the Internet. At some point, you can only get so much traction out of free promotional techniques like Link Trading and others. While these free promotional strategies are critical to your overall marketing efforts, you must use paid advertising resources on the Internet to truly promote your website and drive serious traffic.

Without understanding your key performance metrics, using paid advertising can be treacherous. If you do know these metrics, then paid advertising on the Internet becomes not only viable, but extremely safe and effective.