At what point does legitimate business promotion become spam?

Spam is unsolicited mail, so any message sent to a person who did not sign up for your messages is spam. That includes first contact, notifications and anything else - no exceptions.

In the UK, email lists are opt-in: you are not allowed to email people who do not opt IN, rather than emailing everyone and expecting them to opt OUT.

The US "CAN-SPAM" law (which, amusingly enough was supposed to "can" (i.e. trash) spam, but in fact means you "can spam") allows you to send one email to contacts,

I consider first invitation as not spammng-if i reply positively, you are welcome to tell me more, but if i let you know-i'm not interested, and you continue sending me the same offer over and over again, it is spam.Also, if i get only information abot something-without link or name, and if it is interesting for me-i will ask for sure, so you did not spam me, you only invited me to see something that might keep my eye. And by giving only information-rather than links, provide you to really know

Contacting your companies data base of existing clients is not spam. Asking them to share your website, contact information, etc... is not spam. When you purchase a email list or contact a bulk number of people that do not know you or never have contacted you directly, this is spam (when it is done in bulk)...

spam is when you send to anyone who does not request to be contacted by you.

it became spam when they do not keep there words and perform win time what they guaranteed.

I love SPAM. When I recieve a MLM opportunity from someone NOT on my contact list,
I reply with a "Thank You". and add them to my list. When I send my offer, I ALWAYS add a "REMOVE" in every email.Sending email to people who have not opted-in to your list, or contacted you first, is considered SPAM. Very unprofessional and a waste of time.

There is no such point in time that we could specifically and for sure could tell that ....

I'm trying to define this for inclusion in a possible future article. All opinions are very welcome.?