This phrase is commonly used in the context of card games, particularly bridge. In bridge, "South" is a specific player position. So, "South followed suit" means that the South player played a card of the same suit as the first card played in the trick.
However, the phrase can be used in a more general sense to mean following an example or trend. For instance:
* "When the North American market started selling electric cars, South followed suit and soon had its own models." This means that South America, seeing the success of electric cars in North America, decided to produce its own versions.
* "After the company announced a pay raise for its employees, the competitor followed suit to keep their staff happy." This means the competitor matched the pay raise offered by the first company.
The key takeaway is that "South followed suit" implies copying or mirroring a previous action or behavior. It suggests that the action was inspired or influenced by a precedent set by someone else.