Tracking your visitors is extremely important. If you know how much traffic you’re getting and where it’s coming from then you can optimize your traffic and conversions on your site. That’s why you need to install a web analytics product, right away if you haven’t already.
Google Analytics is probably the most popular web analytics product. It’s a really good service, and best of all it’s free.
However, not everyone wants to install Google Analytics on their site. Mainly, because they don’t want Google to have access to more data on them then necessary.
So what are some good Google Analytics alternatives?
Clicky
Clicky is great. It offers real-time tracking of your traffic. It has a simple, but easy to use interface. It’s easily accessible via your mobile phone, so you can track your stats wherever you are. The Clicky Pro plans starts at $9.99 a month.

Woopra
People really love Woopra’s nice looking interface. It has a web app or desktop client. Plus it has some very powerful segmentation features. I found Woopra a little bit clunky though in my experience.
Piwik
Piwik is a completely free, open source Google Analytics alternative. It provides semi real-time tracking. I saw semi, because when you start getting more traffic, it slows the system down and you have to use their archive feature.

Mint
Probably the best looking web analytics software. Mint is very simple, yet extensible by adding plugins called Peppers. The downside to Mint is that you have to pay $30 for a single site Mint license.

This is just a small sample of the available Google Analytics alternatives out there. Some others you may have heard of like AWStats, I don’t really recommend since their stats are widely inaccurate.
There are quite a few others as well that I haven’t tested yet too. Reinvigorate and Open Web Analytics come to mind. If you’ve used any of these other web analytics products, please let me know in the comments.