One method to promote your website over the internet is sending messages which contain links over the group on the internet. Yahoo groups and Google groups (using Gmail) are well known and have been extremely used over the last few years.
There are several reasons to such promotion:
- the search engine crawlers will parse the message on the open groups and will index their content and the links inside them, it's a very good method to get backlinks for your site
- the humans that read the email might be interested about the content of the link inside the message and they might follow it. Of course, that depends of the subject of the discussion and the information inside the message, if the sender says something useful and/or interesting the readers will try to find out more about the subject.
One mistake I've noticed a few years ago is about the content of the messages. There was a fun group on yahoo and some guy that had a blog with the same subject. He knew some things about the web site promotion and he started sending emails on the group with links of his site. His mistake was the he end only the links and nothing else, no description about the content, no additional information. His bigger mistake was that he send lots and lots of emails with only the links.
For the search engines that action might have been good, the links might have been indexed and followed, but I can tell for sure that it pissed of a lot of people and only handful of people was accessing his blog. In time the guy understood that it was doing wrong (after we was told that a few times) and added more information.
I am telling you never to do something like that. I might work in the beginning, for a few times, but in time you can only get banned on that group.
A more better way is to send a part of the content of your post (some jokes, the first half of the article, for example) and the link in the messages on the groups. If the people are interested they will follow the link. The additional content will make the search engines to index the message faster and considering the link more easier.