According to Business Insider, at Finnish game company Supercell office, there is a strict policy on shoes: NO SHOES IN THE OFFICE. EVER. If you wear a pair of shoes, they must be ones you wear only inside. At Supercell, the management wants the employees to feel like at home and so many of them walk around in socks. Why not!
Source: Business Insider www.businessinsider.com/supercells-no-shoes-policy-2013-11
