Now comes the big question, what does a log analyzer do for you? The first thing it does is allow you to see how much raw traffic you get on a day to day basis. This will allow you to monitor trends such as what days, weeks and months are the busiest for your site. You will most likely already have some notion as to when your busy times are before you look at your stats, but concrete numbers will serve you much better than estimates.
What can you do now that you know when your busy times are? The better question is what can't you do? These types of trends are what traditional industries thrive upon. Understanding your traffic trends means understanding your customers. This information allows you to do things like schedule service outages and promotional campaigns, understand why your revenue is fluctuating, and most importantly know when you can take a vacation.
The data you'll get from your log analyzer will most likely come in more than one parameter. For example, awstats will give you daily stats for visitors, visits, pages viewed, hits and bandwidth. The visits statistic in this case is subjective since a "visit" is not a readily defined metric. A visit is a derived value based on the raw data in your log file. The pages viewed are significant since it is probably the most useful metric to show real traffic levels.
Hits and bandwidth are important metrics, but not to judge success or popularity. These metrics are what will help you manage your server and hosting facilities. Understanding how many hits your server is processing is important for server and client performance. Each time a web surfer loads your page, that person's browser will make a server request for each component of the page. The fewer requests a page requires, the better your site will perform. Bandwidth is another important performance metric since most hosting packages come with a fixed amount of bandwidth per month with extra charges if you use more than your limit. Following your bandwidth trends will allow you to grow your site, smoothly upgrading your hosting solutions without running out of bandwidth or being charged extra fees (which are often more expensive than upgrading to a bigger package).