Foreign Currency revaluation.. Why ?

Hi All ,

AX 2012 R3

AX has the Foreign Currency revaluation functionality for Main accounts , Customers , Vendors , I could understand the concept for Customers and vendors as client purchase/sale the materials to other country vendors/customers , so we need to run the revaluation batch job based on the client requirement.

The question is always companies will maintain the main accounts in the Company currency only , then why we need to run the foreign currency revaluation for main accounts ? Any light from pioneers with an example ?

Thanks in advance.