Each and every website on the World Wide Web is completely different from one another. Something that may work great for one website may not work so well for your site. The first thing you will need to do in order to determine what success means to you and then work the success of your site around those perimeters.
First, you need to figure out what the overall goal is of your site. Maybe you want to sell products or may you want to raise funds for your favorite cause. Whatever the reason is, you need to be sure that you set goals for your website which are challenging but realistic at the same time.
You need to understand how visitors to your website are interacting once they are there. This is called website metrics and something you will need to keep track of from time to time. That way, you can see where the strengths are with your site and where you may need to improve.
Some of the most important metrics that you should be keeping track of include conversion rate, unique visitors, referrers, top keywords, bounce rate, average time spent, top search engine and top internal search keywords.
There is a wide array of tools online that are available so that you can measure the metrics of your website. These tools include Google Analytics, Deep Log Analyzer or Piwik.
When you are in the midst of measuring how successful your website is, you need to remember not only to set goals for your site but also measure how well those goals are working.