reddit is significantly smaller bandwidth-wise than 4chan. reddit doesn't host images. I don't remember exactly but when I left 4 years ago it was only single digit terabytes of outbound bandwidth.

Here is a slightly newer (although still quite old) answer from rram, peak of 924.21 Mbit/sec.

https://www.reddit.com/r/sysadmin/comments/r6zfv/we_are_sysa...

In 2009 Facebook did 25TB/week in just photos, and I imagine it's significantly higher now (particularly with Instagram added).

https://www.facebook.com/notes/facebook-engineering/needle-i...