Purina has a loyalty program – My Perks. When you sign up, you can earn 10,000 points just for registration. Daily login will earn you 10 points. It’s free to join, and you can earn points for every day activities, such as browsing their website, interacting with them on Facebook and Twitter, and reading their emails. Once you accumulate 30,000 points, you can earn a Free Bag of Purina (up to $15.99 in value).
Check out their FAQ page if you have any questions.