Twitter-commerce startup Chirpify has signed up another big name from the music world: Green Day. The band have become the first major-label act to use the service to sell music direct to fans via their Twitter feed.

The band followed their performance at MTV’s VMAs last week with this tweet: “#VMA special! Love the new song? Get it now + all 3 new GD albums, deal ends tmrw Reply “buy” for $29.99 via @Chirpify”.

Fans who signed up for Chirpify and connected it to their PayPal accounts could make the purchase.

Handily, the public nature of the transaction means it can be tracked: a Twitter search for “@GreenDay buy” reveals that 126 people took advantage on 7 September when the deal was tweeted, and another six the next day.

So just under $4k in gross revenues IF all those people had Chirpify accounts, from a Twitter following of 2m.