What you're going to need to do is take a long hard look in the mirror and ask yourself what you want to get out of your website. If you're looking to create a site that will make you lots of money, you will probably have different expectations and goals than if you operate a site meant to deliver a message as its primary function with cost as a secondary concern (think government web site).
This part of the process is crucial as the clearer your intent is at this point, the easier it becomes to clearly spell out achievable goals further down the road.
Now that you know what you want your site to do for you, we need to start setting some goals by which you'll measure the success of your website. This is a point where people often make mistakes by substituting their dreams in place of well thought out goals. It's important to have dreams for your site, but realistic concrete goals will be a far better path to growth and a much better tool to gauge the success of your website on the way to achieving those dreams.
Let's talk about some of the questions you'll need to answer if you're looking to set goals for financial success. What about break even points for starters? How much traffic do you need to make $1? How much money do you need to bring in every month in order to break even? Is it achievable? How much more room for growth is there after you break even? Are your sales directly related to traffic volume?
If you don't answer all of these questions and more, you will have a difficult time reaching your goals. Traffic alone will not necessarily let you reach your target. Some people have very successful sites with a handful of loyal visitors, while others can have thousands of visitors per day and be barely paying the bills.