Steam Spy is a site which estimates owners, players, and playtime for all games on Steam – data that Valve keeps secret. It does this by scanning around 800,000 public user profiles per day then extrapolating for the entire Steam userbase. Many developers have said SteamSpy’s estimates broadly line up with their actual sales figures, though some have found it less accurate. Seeing as Steam Spy draws from game lists on public profiles, setting this private by default seems to kill the site.
“Steam Spy relied on this information being visible by default and won’t be able to operate anymore,” owner Sergey Galyonkin
tweeted last night. The number of people who now choose to set their profiles public would be too small and too self-selecting to be useful data, and it
sounds like other possible techniques would be too imprecise and too much work. “I’ll probably still keep the archive,” he
added.