It could be a small surge but something where you noticed a sudden influx of people. Maybe a game you were playing that got quite popular after it was streamed or there was free weekend on Steam.
For example during the quarantine and around the time when the used console market got prohibitively expensive handheld emulators like the RG350 and much later the Miyoo Mini got quite popular. This was partially due to more people at home wanting to play their favorite classics but also them being promoted as “fake” GameBoys and PSPs on TikTok.
Science fiction conventions. Back in the day, a World Science Fiction Convention (“WorldCon”) was incredible when the reached over 1000 people. New York Comic Con has almost 180,000 people last I checked. And adjacent to that, anime. It used to be niche weirdos in basements in the US but now in an enormous industry.