Why your website needs Analytics

You have a website or a blog. Do you know how many people visit it? When? From where? Do you know what and how they are doing? What type of browsers do they have?

Apparently, not every blog or website owner does. So here is the short explanation.

Web analytics software allows to log every visit to your website and present data about visitors in useful manner.

What can you do with it?

Know how many people actually use your site.
Do you know it already? If you don't, than why? Do you have a site for yourself or you intend to reach at least someone? This is the most important metrics of success of your site and especially the changes on it. Did you do a redesign? Did you fire one of the writers? Did you start a marketing campaign? Did you write super-successful blog post? You can notice the result of the change on this graph. See the example:
The visits pattern was steady (with regular drops on weekend), and then something very positive happened in July - and site has gotten much more traffic.
Know where people are going on your website.
That's how I know, for example, that my most popular blog post is about blind search (and it got three times more traffic than second most popular post about Microsoft IE8 campaign).
Know where people are coming from.
This is how I know that a single link by dolboeb gave my site twice as many visits as a link on a homepage of BarCamp Baltics (it was there in February, gone now). And that's how I know that people are really interested in how is Chrome doing on Linux, since they are searching for [chrome linux status] and arriving on my post (sadly, not very informative for them).
Know how well is your site connected and how sticky it is.
Do people just arrive at your site and leave in horror or do they surf around and read your stuff? I know that my visitors leave the site after the first page in 82% of the cases, and spend 1 minute 20 seconds on it on average.
Know who you visitors are.
I know that my visitors are definitely not an average folk, since only 11% of them use IE, and full 20% use Chrome; 12% of them are visiting site from Linux. I know that 19% of them are in Russia, 15% in Belarus and 13% in the US (and 25% of those in the US are in Mountain View, California).
Know what you can and what can't do on your website.
I know that less than 15% of my visitors have resolution 1024x768 or less; therefore, I could widen my design to accomodate Google Moderator iframe in the post about tech press rating. It's a pity to see some sites that still use less than 800px width, even though just a few users really need this.

This is just a short glimpse into what you can do with analytics software. As anyone who is in PR. advertisement or sales knows that knowing your customers (or, in this case, readers) is a key to reaching goals.

Ah, and the actual practical info. The screenshot above is from Google Analytics; I use it since I started this website and happy with it. To use it, you need to be able to inject a piece of JavaScript into template for every page of your site (this is why you can't use it on LiveJournal, and one of the reasons why I had to move away from LiveJournal). There is other analytics software around - like WebTrends (or see the long list), but I didn't try those and can't say much. Whatever you choose, make sure that you are interested in your website - otherwise, why should your visitors be interested in it?