I think this is all important advice, however I still think people need to understand the commitment they make to a pet. Rehoming an animal is extremely hard on them. There are certainly very necessary times that a pet needs to be rehomed; I do understand this. But all too often pets end up being rehomed because they are inconvenient. Once the novelty wears off, and people realize there is a fair bit of work involved, pets often end up in a classified ad.
So, even before someone gets a pet, think of what is involved, and then think of the responsibility one should try to keep to their pet.
It would be so much easier if pets were only rehomed when it is very necessary, not when they become inconvenient.