Monthly stats-how many visitors came to your site during one month. These will be divided into unique and general (repeat visitors).
Weekly stats- how many visitors came in 1 week, again they will be divided into unique and general
Daily stats
Hourly stats

This is a good estimate of the quality of your site. Obviously the longer your visitors stay the more chances there are of them buying. Once you know which pages are attracting visitors you can then work on getting all your pages sticky and compel surfers to visit them.

Google also tracks how long visitors are spending at your site. Again it is a quality check as far as they are concerned. When Googlebots bring information back to the Database about a website being visited and people are staying longer, they can naturally assume the standard of that website is high. High standard and quality means Google customers (your visitors) are being serviced well and that makes Google happy. This will earn you a higher Page Rank.

Encourage a longer stay:

So we can naturally assume that the longer your visitors stay the better it is. Now how to encourage them to stay? Have you ever read a book that you just could not put down? Well you website must have that same effect on your visitors. They will not want to leave until they have devoured every word of your pre selling content. They should be in the mood to either sign up for your free newsletter and become your leads or go on to your sales page and buy your products or services.

Making them stay: Make your site an irresistible, sticky website that draws your visitor in and compels them to stay. Here are some ways:

1. Interesting informative content
2. Stories, anecdotes, and news about your industry
3. Quizzes relating to your industry-the answers will be found on one of your important pages
4. Good user friendly navigation
5. Humorous jokes, quotes and stories related to your industry-these are often shared among friends and associates (viral marketing).