AI in the Enterprise: How People Use M365 Copilot Chat. - Scott Counts; Yan Chen; Jing Dong; Himanshu Sharma; Andrey Zaikin; Rui Hu; Alperen Kok; Gorkem Ozer Yilmaz; Siddharth Suri; Kiran Tomlinson; Sonia Jaffe; Will Wang (CoRR, 2026)