The consequences of a single opt-in if something goes wrong

I'd love to know the consequences of what actually happens in the worst case scenario if you use a single opt-in.

I read the reply from Insofusion in the double opt-in thread and was quite surprised by the answers.

For instance, the deliverability rate is 99% for double opt-in, while single sits at 97%.

That's pretty big if you take into account that having 10,000 on your list means you lose out on 200 emails.

What I don't like is the fact that if 10,000 people tried to join your list, 6,000 would actually end up on your list using the double, and you'd get the full 10,000 using single opt-in.

So 97% of 10,000 is a lot more than 99% of 6,000.

If you take into account that 6,000 on the single opt-in would have joined with a double opt-in anyway, it means you have an extra 4,000.

Out of those 4,000, some may be fake emails, some just wanting a freebie, and you're left with people that might read your emails and buy something.

So it comes down to whether those 60 undelivered emails in the first instance (99% of 6,000) would bring in more income than the extra 4,000 in the single opt-in that actually get your message.

Let's just say that you would make more money using single opt-in, what would happen if you got spammed or something else not very nice?

Would you get your list deleted without question and your business ruined, or would your email company check what you're sending and decide on a case by case basis whether you actually did anything wrong?

And if someone was spamming you with bad emails, could your company detect and delete those emails from your list, or would your deliverability rate drop to zero?