[1] Thin had previously worked for 12 years for James McIntosh, a bookseller at 5 North College Street, having joined the firm as an apprentice at the age of eleven.
[2] On 3 April 1848, Thin opened his own shop, at 14 Infirmary Street, having taken over the assets of a Mr Rickard, a bookseller who was in financial difficulties.
[4] Trade continued to improve and Thin was soon advertising the business as "the largest retail bookselling establishment in Edinburgh".
In 1970, Jimmy and Ainslie Thin established the Mercat Press imprint, specialising in books with a Scottish interest.
[4] By 2007, Mercat Press had over 200 titles in its list, these being predominantly works on architecture and heritage as well as guides books and general fiction, the latter category including the novels of crime writer Gillian Galbraith.
In the 1980s, Ainslie Thin developed a version of the system in dBASE III to run on personal computers within 26 of the shops.
[1][4] In 1998, the company started selling books on line, making it what at the time was described as "the biggest on-line bookseller in the world".
[11] It was also the first bookseller to use the Whitaker TeleOrdering system[9] James Thin Ltd.'s annual turnover remained at about £35 million throughout the 1990s, but then declined rapidly.
[9][12] Jackie Thin, the managing director, blamed the collapse on increased competition, falling turnover and the cost of closing loss-making shops.
[15] In April 2002, Blackwell UK announced the purchase of Thin's twelve academic bookshops for "in excess of" £2 million, with all of the 102 staff retaining their jobs.
[13][16] Thin's publishing arm, Mercat Press, continued to trade as an independent entity following a management buy-out.