This is something that is important. 

In prospecting some of the time you invest a lot of time trying to get the phone numbers of companies. When you use the lead tab if you don't have a current potencial opportutinity fo r a certain lead, either you convert them to an opportunity or you archive it. 

This information is valuable and should not be lost in pipedrive unless you want to.

I personaly don't understand why the use of archive