Chirpify is best known for being a service that helps bands sell music and merchandise to their Twitter followers. Now it’s moving into Facebook commerce too, with country star Tim McGraw one of the first artists to try it out. He’s promoting a special edition of his ‘Two Lanes of Freedom’ album with a status update on the social network, inviting fans to reply ‘buy’ to buy the album for $15.99 plus shipping. They have to be registered users of Chirpify for the scheme to work, though. The deal puts Facebook alongside Twitter and Instagram as venues for Chirpify to sell products on. “Chirpify is enabling in-stream commerce by comment on Facebook for select top tier brands and musicians before a wider rollout and official launch,” CEO Chris Teso tells CNET. McGraw’s album sold out within 24 hours of his post, although it’s unclear how many copies were available.