spammer address collecting?

so i get an email from a friend which has been forwarded say a half dozen times, at least, before it reaches me.

body of email is:
> {title}

> {several paragraphs of email addy’s of previous forwards}

>this really works!!!1111!!!

>{couple paragraphs of stupid joke, or “test”}

>{for punchline / answer, forward this message to (either “your entire mailing list” or “[x number of] people” then hit [keystroke alt+(something or other) or etc.]}

>
>

so, i know it’s just some stupid chain mail thing. i never forward them on. i usually delete them on the spot. and i often mention to email correspondents that i do not appreciate receiving random forwards just because i’m on their contact list.

anyway, i’m wondering whether the source or purpose of these types of messages are (usually? often? perhaps?) spammer-mailing-list-compiling related, and how effective they may actually be, if indeed that is the case.

Internet Spammers or other people who want to collect lists of e-mail addresses can use these things to get valid e-mail addresses. Don’t ever forward these things.

When I get these things, I take note of who sent them to me, and who they sent them to.

I fix computers, among other things, and these are a good indicator of where my next job is coming from.