Webinar Roundup: Building Your E-mail List

"Don't have one message that's got a different subject line and a different length and a different call to action, or you won't really be able to tell which of those things that you were playing with had the best effect," he noted.

Segmentation involves separating out groups within your e-mail list (new members, or donors above a certain dollar value) and sending them a more tailored message that relates to them more specifically. Be sure to test the messages you send to your segments to make sure they're having the desired effect.