UPDATE: SimGuruDaniel revealed some more info on flea markets:

@Quaay00 You can run your own sales tables. — Daniel Hiatt (@SimGuruDaniel) September 26, 2016

It seems that The Sims Team wanted to keep a certain feature secret until they’re ready to talk about The Sims 4 City Living’s Festivals. Still, one of the retail websites managed to leak a huge feature that you’ll be able to play with.

British gaming retail website GAME has provided an extended description of Festivals:

Discover Lively, Cultural Festivals: Enrich and grow your Sims by taking them to different festivals all over the city where they can watch street performers, enter competitions, and meet different walks of life. Take your Sims to the Spice Festival where they can enter the Curry Challenge and become the Spice Master. Help your Sim light fireworks with a hot date at the Romance Festival. Earn Simoleons by selling your Sims’ crafts at the Flea Market.

It’s still unsure which crafts we’ll be able to sell and will we be able to craft entirely new objects.

Flea Markets were first shown in the early designs of The Sims 4 Get Together’s Windenburg, still, they didn’t fit in with The Sims Team’s vision of Get Together Expansion Pack.

Tip: @TheSimScraper