In your scenario, Alice already decided not to buy anything from AcmeShop.
Even if AcmeShop advertised on Facebook it wouldn't have changed her behavior. She got a better deal on Facebook Marketplace. And she was already visiting Facebook and the Marketplace is already a single click.
I don't see the abusive or predatory part. It seems like Facebook Marketplace just offered a superior used 3D printer for her.
In your scenario, Alice already decided not to buy anything from AcmeShop.
Even if AcmeShop advertised on Facebook it wouldn't have changed her behavior. She got a better deal on Facebook Marketplace. And she was already visiting Facebook and the Marketplace is already a single click.
I don't see the abusive or predatory part. It seems like Facebook Marketplace just offered a superior used 3D printer for her.
So what part am I missing?