Shaepoint 2013 : Active Directory Import

Hi1

We are setting up a demo farm for a client for analysing sharepoint 2013 .

What exactly are the advantages  of Active Director Import?  is it one time or can we run it weekly so as user profiles keep upto date?

http://blogs.technet.com/b/meacoex/archive/2013/08/04/step-by-step-active-directory-import-for-sharepoint-2013.aspx