When I just started out on reddit, I was self-promoting very aggressively, even on this sub. I was pasting my website url everywhere. And truth be told, my traffic shot up. For a full 3 days.

Then reddit banned my domain. This was a year ago. My domain is now so banned, I cannot even use it in DMs.

I do however see people, posting their website links on reddit, and reddit not banning their domains. So there must be some acceptable tolerance/ratio.

reddit Answers claim a 9:1 ratio, so from my understanding, you are allowed to post your domain, every 9 answers you give.

Does anyone have any insights or experience regarding this, please?

This ratio, how much promotion is acceptable on REDDIT, not a sub like SEO that has a zero promotion policy.