- Web browsers used by your visitors
- Where your visitors come from
- Screen resolution used by your visitors
- Operating systems used by your visitors
- How your visitors found your website
- What keywords where used by visitors in a search engine to get to your website
Web browsers used by your visitors - by knowing which web browser your visitor uses, such as Firefox, IE, Chrome, and a lot of other freely available browsers, you will be able to know which web browsers you should be focusing on.
Where your visitors come from - this is very important especially if you're targeting a certain audience.
Screen resolution used by your visitors - this is important because on average a visitor takes only a second to decide whether his in the wright website or not. So it is important to know how much he is seeing the moment he enters your website. So knowing your visitors screen resolution will be crucial to determining how you should design your website or blog.
Operating systems used by your visitors - most often, the technology you use in developing your website or blog can be very "platform dependent" meaning that it can only work in one kind of operating system. So it is important to also take note of the different kinds of operating system your visitors are using.
How your visitors found your website - this kind of data is very important when determining which of your efforts are paying off. It basically shows whether your visitors found your website directly, through referral from other websites which might have linked to your website, or from search engines which would mean that your doing a good job with your SEO.
What keywords where used by visitors in a search engine to get to your website - this is crucial for your SEO, knowing which keywords your blog or website has been found can determine if you are on the right track.