Memory Stick Duo

Memory Stick

From top to bottom: Memory Stick PRO, Memory Stick PRO Duo, Memory Stick Micro (M2)
Media type	Flash memory card
Capacity	128 MB (Original) 32 GB (PRO Series) 2 TB (XC Series)
Developed by	Sony
Extended to	Memory Stick PRO, Memory Stick Duo, Memory Stick Pro Duo, Memory Stick PRO-HG Duo, and Memory Stick Micro

Memory Stick is a removable flash memory card format, originally launched by Sony in late 1998. In addition to the original Memory Stick, this family includes the Memory Stick PRO, a revision that allows greater maximum storage capacity and faster file transfer speeds; Memory Stick Duo, a small-form-factor version of the Memory Stick (including the PRO Duo); the even smaller Memory Stick Micro (M2), and the Memory Stick PRO-HG, a high speed variant of the PRO to be used in high-definition video and still cameras.

As a proprietary format, Sony exclusively used Memory Stick on their products in the 2000s such as Cyber-shot cameras, VAIO PCs and the PlayStation Portable, with the format being licensed to a few other companies early in its lifetime. With increasing popularity of SD card, in 2010 Sony started to support the SD card format, which was seen as a Sony loss in the format war. Despite this, Sony continued to support Memory Stick on certain devices.

The original Memory Stick, which was launched in October 1998, was available in sizes up to 128 MB.

In October 1999 Sony licensed the technology to Fujitsu, Aiwa, Sanyo, Sharp, Pioneer and Kenwood, in a bid to avoid a repetition of the Betamax failure. Other companies were also licensees to the format. Some early examples of Memory Stick usage by third-party companies include Sharp's MP3 players, Alpine's in-dash players, and Epson's printers.

Initially the format had a lukewarm reception, but it soon increased in popularity, especially after the licensing deal. In spring 2001, Memory Stick attained 25% market share (against CompactFlash's 40% and SmartMedia's 32%), up from 7% a year earlier. By May 2001, total shipment of Memory Stick units surpassed 10 million.