Here's rule #3. Click on the link to read the other rules.
3. Limit the emails you send from your group or fan page to, at the maximum, one per month. Please send them less often than that. I want to join your group or fan page and show you that I support you and your work, but I really don’t need to know every single thing you do. Presses, especially– please condense this kind of stuff into a monthly newsletter. And please try to ensure that you don’t send me the same thing more than once.