westjet is becoming a lot more cautious about transferring credits. due to the criminal behaviour of that man in BC about two years ago they have been tightening up their system of transferring credits.
yes, YOU can purchase a ticket for another person but if they need to make a change and receive a credit, they will return it to the profile of the original passenger.
this is only great for people who know whom they are dealing with and if need be, can contact the transferring party if changes need to be made.
they may offer a direct credit if the new traveller pays a difference of more than $100.00--but as of yet it is unconfirmed so I wouldn't rely on it.