On January 8th, Steam hit 18 million concurrent users, a new record for Valve’s PC gaming service. (18,363,471 to be exact at around six in the morning Pacific Time.) That’s up about 4 million from a year ago. About 3 of the 18 million souls were trying to get into PlayerUnknown’s Battlegrounds, making it the most popular game on the client. In second place, Dota 2 with approximately 765,000 players, has a long way to go to catch up. If Valve doesn’t watch it, this Steam idea may catch on.