I hope you realize that there is quite a difference between simply wanting or liking something a whole lot, and being addicted to something.
KFC does not seek to prey on the (hypothetical) few who are so addicted to fried chicken that they lose their families, sell their valuables, lose their careers, and sell their bodies to get another fix. They "prey" on people who like their product.
Real addiction (not your perverted sense of "addiction" being merely liking something intensely) is a hypothetical side effect of the businesses you give as examples. For the gambling industry and companies like Zynga, it is the business model.
KFC does not seek to prey on the (hypothetical) few who are so addicted to fried chicken that they lose their families, sell their valuables, lose their careers, and sell their bodies to get another fix. They "prey" on people who like their product.
Real addiction (not your perverted sense of "addiction" being merely liking something intensely) is a hypothetical side effect of the businesses you give as examples. For the gambling industry and companies like Zynga, it is the business model.