Just got this question from a new member of my LinkedIn network today, so I thought I would share my answer with everyone.
If you have something you want to tell everyone, or something that you want to sell, it makes sense that you want to go beyond your first level network to the millions (in my case almost 18 million) of people that are in your 2nd degree and 3rd degree network. But how to contact those in your 2nd degree and 3rd degree network directly, all at once, in an efficient manner?
Unfortunately, this cannot be done, and LinkedIn intended it to be that way in that they want to limit what they see as potential spamming.
As you probably have figured out by now, you can download your 1st degree connections from your “Contacts” or “My Connections” screen and then contact all of them at once.
If you are a LinkedIn Group manager, you can download all of the group members and contact them at once. (note: LinkedIn has since discontinued this functionality)
Other than that, the only way to contact 2nd degree and 3rd degree connections is to:
1) send an InMail, for which a paid account is necessary
2) if you are in the same LinkedIn Group with them AND they have allowed Group members to access their email address you can send them a message, or
3) you can find their email address if they have listed it on their profile.
Unfortunately each of these methods must be done on a one-by-one email basis.
The only other way of advertising what you are doing is:
- Putting it on your profile
- Asking questions about it in Answers
- Conducting a poll on it
- Starting a Group
- Placing messages on Group Discussion Boards
Contacting 2nd degree and 3rd degree connections is not easy, but following the above steps you should be able to contact those that you feel are strategic to your objective. I realize that there are no quick fix solutions here, but part of the challenge (and fun!) of working within LinkedIn is to find creative ways around the barriers. Let me know if I missed any!