Who would trade a commission-based over commission-free for the same currency pair?

External question — Personal Finance Stack Exchange Author: huab Original post: https://money.stackexchange.com/questions/145551 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. (I'm a beginner) In forex, I see that some pairs are both commission and commission-free, what is the difference?