BBM ID is your email address, used for a number of Blackberry services including logging into BBM. A BBM PIN is a unique to-you eight digit number or alpha/numeric code that is either automatically provides when you buy a Blackberry phone and is recorded in the device, or in the case of iPhone/Android BBM, provided to you when setting up BBM on those devices. The PIN is the backbone of BBM; it provides for direct PIN to PIN data transfers, and you do not need to provide an email address to others to have them on your BBM, just your PIN, increasing privacy.