In the UK there was a brief period from 2009-2011 where everyone seemed to replace their Nokia with a Blackberry before iPhones became common (BBM was a big thing)
I can remember one Christmas, perhaps 2010, where my Facebook feed was just folks posting their BBM pins. Ah, what a throwback.
In retrospect, a better idea than giving out your phone number as WhatsApp requires. And indeed, people were more willing to share BBM pins than phone numbers.
https://www.theguardian.com/media/2011/aug/08/london-riots-f...
https://www.telegraph.co.uk/technology/blackberry/8688651/Lo...