Hi,
Yeah, the credit is the points - in this case 481 points.
However, these WU (and all the other SMP core_A3 and core_A5 ones) also qualify for Quick Return Bonus Points.
Basically, there is a sliding scale that rewards quick return with more points. This is done to encourage people to just run one client quickly, rather than multiple ones more slowly.
However, to qualify for these bonus points (that are often worth 10 times the base points), you'll need a passkey - see here:
https://forums.macrumors.com/threads/1073565/
You can calculate how many points you expect to receive here:
http://linuxforge.net/bonuscalc2.php
Hope that helps
Rob