Originally Posted by Starwood Lurker

It's called a "Loyalty" bonus because it was formulated to get people to use the card. The 50%/50% aspect comes from American Express paying half the cost and us paying half the cost of the Starpoints being issued.

You had to be targeted by American Express to get this bonus and not everyone was given the same bonus amount, so that is why some have gotten it and some have not or why some bonuses are greater or smaller than others for those who did.