In T15719#15280, @avivey wrote:

This suggests to me that there isn't a third category - everything is either promotional or transactional.

I'd argue that none of our emails are "marketing" or "promotional" (or "commercial"), even if it's hard to claim they are "transactional".
But as long as 98%[1] of the users agree that our mails aren't commercial, we don't need the one-click solution.