Whenever I add a contact to BB messenger it does it via their email address, how do I add them based on their PIN?

Is there a difference between the two?

Highlight the name in BBM and hit the menu key not the trackball and add via PIN...

There is no add via PIN option when I click menu.

If you have the contact's PIN saved in the Address Book, you should have a 'Request (PIN)...' option when you highlight their name and press the menu button.

If you don't have their PIN in your address book, but you know what it is, you can click Add a Contact, then highlight [Use Once] at the top of the address book, press the menu button, and click Request by PIN.

It seems lately when you don't have someone's PIN saved in contacts BBM doesn't work properly.