The test has started in the US, Mexico and Brazil. Facebook didn't outline its expansion plans, but it won't be shocking if it spreads to other countries.

In a sense, Facebook is acknowledging both the limitations of its current event system and the realities of modern social networking. It's hard to advertise an event beyond the initial invitation. With Stories, it's easier to offer periodic reminders and sell people on the concept beyond a plain text description. And simply speaking, this is the Stories era. The addition of events makes sense for people who've practically grown up with Instagram and Snapchat, and might spend more time looking at friends' Story clips than browsing their news feeds.