Since many users are trying to develop business or looking for jobs, almost everyone receives a lot of spam messages from Linkedin users that are not very Linkedin savvy. There are tons of people out there, who usually add random contacts on Linkedin and send them a mass copy-pasted message.
I once received a spam from a person working in my industry. He kept sending me spam and follow-ups for a week. And after a week, he sent me a message to throw me off on a guilt trip and deleted me from his contacts list. Good riddance.