Newly published book Kapinallinen kauppa (Siltala 2015), written by Anitra Komulainen, Markku Kuisma, Sakari Siltala and Teemu Keskisarja sheds light into the history of retail in Helsinki. The two protagonists of the book, Helsingin Osuuskauppa ja Elanto, started off in 1905 as one cooperative store, but in 1918 the business split up. The first started serving the bourgeoisie customers, while the working-class preferred cooperative store Elanto. The two retail businesses grew and flourished separately throughout the 20th century, but surprisingly merged again in 2004.
More about the book from the publisher’s site (In Finnish)