Spammers aren't necessarily evil, but definitely annoying, and annoying customers is a good way to lose them. It's easy to drink the coolaid and eat the dogfood when you're paid to like it or have a passion for creating it but potential customers have roughly the opposite incentive and it pays to remember that.
I receive a lot of unread, unwanted email from companies I pay money to every month. It's ridiculous.
There is no "and". If you default opt-in users, you're a spammer.
> Spammers aren't necessarily evil
What?
Everything should require a confirmation before you assume it's valid. Not because it doesn't exist but because it might not be who you think it is.