There are several statistics that I recommend site owners pay attention to on a regular basis. They are: number of visitors, referring sites (where did those visitors come from), keywords (what keywords did they use and top content (what content was the most pertinent to your visitors.
Another statistic to pay attention to is the Bounce Rate. On Google Analytics, Bounce Rate is defined as:
Bounce Rate: Bounce rate is the percentage of single-page visits (i.e. visits in which the person left your site from the entrance page). Bounce rate is a measure of visit quality and a high bounce rate generally indicates that site entrance (landing) pages aren’t relevant to your visitors. You can minimize Bounce Rates by tailoring landing pages to each keyword and ad that you run. Landing pages should provide the information and services that were promised in the ad copy.
Pay attention to your bounce rate – particularly if you are paying for advertising. A high bounce rate means that most people are NOT finding what they expect to find on your website.