The Pope is offering time off in purgatory to people who follow him on Twitter.
Purgatory is the place where practicing Roman Catholics believe they will go after death, as long as they are "in a state of grace" having confessed and been absolved of their sins.
The "indulgence" offer comes ahead of Pope Francis' trip to Brazil next week.
It applies particularly to those Catholics who click on to his Twitter feed on Catholic World Youth Day, a week-long event that starts on July 22.
Indulgences are given against the time believers may spend in purgatory following their death - the more indulgences they are granted, the less time they get to spend in the "halfway" house between Earth and Heaven.
"You can't obtain indulgences like getting a coffee from a vending machine," the Vatican's Archbishop Claudio Maria Celli told Italian newspaper Corriere della Sera.
"What really counts is that the tweets the Pope sends from Brazil or the photos of the Catholic World Youth Day that go up on Pinterest produce authentic spiritual fruit in the hearts of everyone."
The Sacred Apostolic Penitentiary, a court set up to deal with the forgiveness of sins, is encouraging people who cannot afford to see the Pope in Brazil to follow him through the TV or internet.
But it stresses events must be followed live, with proper devotion, and a casual websurf will not win any time off for good behaviour.
Indulgences fell out of favour in the Middle Ages because corrupt churchmen gave them in exchange for money.
They were a contributory factor to the setting up of the Protestant church, where the idea was that the believer had a direct conversation with God, rather than through a priest who interceded on his or her behalf.