Google Apps for Business offers much more benefits than the use of Gmail, as you can see below:
- Using Google Apps also allows you to use other features like Analytics, Calendar, Docs and Sites.
- Being a cloud application you can have access to all your emails, documents, manage your sites and see your analytics from any computer with internet.
- Collaborating and sharing information with Google Apps is very simple. In features like Google Docs multiple users can edit the same file at the same time, add annotations and track revisions history, with Google Sites it is possible to create an Intranet or websites for teams or projects where all people can see the calendars, deadlines and all the relevant information.
- Data is 100% hosted by Google, so they guarantee an up-time rate of 99.9% of time.
- In GetApp.com you can find a list of web applications that integrate with Google Apps.

Source: http://computerinformationsite.com/20...