Several of the previous 100-point "read-me" offers have been specifically for CO Mastercard holders. I noted that they appeared to allow everyone to register, but family members without the CO MC did not get those points.
This PetPass / PetSafe one is not targeted, so it appears to be good for everyone. Another good thing -- you didn't need to be signed in to register for it if you were on the link page!
Think positive and plan on getting 100 pts.