This is used on social media, particularly Instagram, as a polite request for someone to follow you back after you follow them. It's basically a short and sweet way of saying, "I'm following you, please follow me back."
However, depending on the context, it could also mean something else entirely.
Here are some other less common meanings:
* "So for sure" - This is used to emphasize agreement or certainty.
* "Same for sure" - Similar to "so for sure," but used specifically when agreeing with someone else.
* "Street Fighter 5" - This refers to the popular fighting video game.
To understand the meaning of "SFS," you'll need to consider the context in which it's used. If you're unsure, it's always best to ask for clarification.