Pretty much any business which is active online in any way should have a standard analytics package installed which provides statistics on website visitors. These core standard analytics applications are often called clickstream due to the fact that the tracking and analytical reports are all based on recording user click activity within a website.
Google and Web Analytics
Google has pretty much dominated the small business market with its free Google Analytics Product
The other Analytics Providers
The other main website analytics products are very much aimed at the Enterprise level clients since Googles free model has priced them out of the small business market.
A few other other big players in the analytics space are Web Trends Adobe site catalyst and IBM Core metrics which are all bringing their core analytics offering into wider marketing packages offering advanced and specialist analytics in the mobile and social space as well as other features such as Ad campaign optimization, usability testing and online personalization delivery based on user experiences and user tracking
Adobe SiteCatalyst (now part of Adobe Digital marketing Suite)
AT Internet (an application in Saas mode with free updates)
IBM Core Metrics (part of IBM Enterprise Marketing Management)
Intlock CardioLog (specific to SharePoint installations)
Webtrekk (offer a SaaS version)
Web Trends (offer a self install version and a SaaS version)