Don’t treat your newsletter as a sales advertorial. Provide a sample of your newsletter on your registration page. Marketo has some good tips on designing emails for mobile users. Syndicate your email content via social channels like Facebook and Twitter (directing to a Web version of the newsletter). Just because someone “Liked&# you on Facebook, followed you on Twitter, or showed up in your Outlook database does not mean you can add them to your newsletter distribution list. Some we look forward to all month, some we trash right away.