Twitter has branched into the market for electronic payments, unveiling a mini credit card swiper that plugs into the iPhone, at a European internet fair on Wednesday.
Twitter's founder Jack Dorsey said the device, the "Square," aimed particularly to enable small transactions for "people like babysitters, dog walkers, golf instructors, flight instructors" to collect payment.
The small black square plugs into the phone's microphone socket, turning it into a card reader like the swipe machines widely used in US shops and restaurants. Its official launch is set for March.
"A lot of people in the world today are using plastic cards to pay people with... But receiving payments from them is very hard," he said while demonstrating the device at LeWeb, an internet forum in Paris.
"There's a number of people who are providing services, or selling something, that can't transact with credit cards today because of the complexity."
Specialist website TechCrunch reported a "feeding frenzy" of investor interest around the Square even ahead of LeWeb.
"This is a bold foray into a huge, and complicated, market: physical payments," wrote Techcrunch blogger Michael Arrington. "Square will be a huge win or it'll go out of business."
Billed as Europe's top internet fair, LeWeb was expected to draw 2000 visitors including major names such as networking site Facebook and Google plus start-ups looking for investors, its organisers said.