The Vatican offered that a shorter stay in Purgatory—if not full salvation—was in the cards for anyone who followed him on social media. Specifically, the Sacred Apostolic Penitentiary announced that indulgences will be given to those who follow the Pope on social media and specified following the Pope’s Twitter account as one such means. (To be fair, the Vatican said that following Twitter on its own was insufficient, as confession, prayers and Mass attendance were also expected.) Getting out of purgatory for some Catholics is worth quite a bit and following a Twitter account seems a small price to pay. That's really hard for Target or Home Depot to match. Then again, if the Church slipped up and didn't deliver the promised indulgences to some followers, they're likely to not learn of the oversight until it's too late to complain.
Retailers have tried quite a few creative tactics to get shoppers to participate in the chain's social media efforts, but none have the clout to do what the Vatican just did when it was trying to boost social media presence: a promise of an afterlife upgrade. (Yes, the Pope—the real Pope—actually did this. We triple-checked because it really does sound like something The Onion would come up with.)