Steam now has over 75 million active users, a significant jump from the 65 million Valve reported
last October. The news was shared with attendees of the company's inaugural Steam Dev Days
While Valve invited few to no card-carrying reporters to the conference -- presumably to help foster the "relaxed, off-the-record environment" advertised -- attendees seem to be posting significant excerpts of the various talks to Twitter using the hashtag #SteamDevDays
That's how we know that Valve is reporting more than 75 million active Steam accounts, and is encouraging developers to bring non-gaming software -- music players, video streamers, etc. -- to Steam Machines.
We also know that each of the roughly 2,000 attendees will receive a free Steam Machine during the conference, courtesy of Valve.