"We of course also limit the subreddits your ads can show on outside of the targeted subreddit to ones that are similarly "brand safe" to the ones you are targeting."

How exactly do you evaluate "brand safe"? I can rarely get my own marketing department to a decision on this sort of thing in less than a few hours, yet you seem to be claiming you can do this on the fly for many advertisers.

Yes, I have noted that your definition of "brand safe" seems to be rather narrower than mine 8)