It's meant to slowly acclimatize people to an idea that they otherwise would violently reject.
Goal: tracking chips implanted in the human population.
If you come at it with "everyone needs to go get a chip," there will be riots.
If you come at it with "every child is required to get a chip along with their childhood vaccines to enroll in school" people will find ways around it.
If you come at it with "every child must be chipped at the hospital directly after birth" people will just go en masse to unregistered midwives.
You have to sell it to them as something that not only is not repulsive, but that they will clamor to obtain.
So you warm them up to it with pets. Here's a safe and easy way to track your pet if he gets out. You make it cheap and bundle it in with other services the pet is already getting, so it just becomes a routine that most people nod along with rather than something they apply critical thought to.
Once people are thoroughly accustomed to this, and anyone who questions it is tarred as an irresponsible loser and weirdo, you can start nudging it closer to the goal.
You could start selling it as a perk for extra elite smart people at first. Prudent, security-minded parents get their kids chipped- then you don't need to rely on smartphones or other bulky, more expensive and risky tech, and you always have peace of mind!
Then you can start nudging it into the routine care package. CDC recommends at this age: Hep B, TDaP, HiB, microchipping...all for safety and just in case...