Microcopy: OMGPOP’s Draw Something says “we will never share your e-mail with anyone” in a very obvious fashion. In your face (and slightly irritating maybe), but could work.

Simple: @Zaarly’s way to get quick ratings into their system for past zaarlies. You just add your ratings and reply to the email.

Proactive: @Spotify’s reaction to a problem they caused their users.

Via Milann. 

Email support: ifttt’s (@ifttt) support emails are followed by a “follow us on Twitter: @ifttt”. Since you’re in touch and helping people out that are interested in your product you might as well remind them of another way to follow you.

Email: Readmill (@readmill) takes another approach to the do-not-reply@ email address: their address is called please-reply{at}readmill.com.

Preview/personal: Artstack adds the recent activity (by the person that invited you) to the invite email. Makes sure you can relate and understand what it’s all about right away.

Sign ups: Asana (@asana) shows you the progress you have already made to being signed up. 

If you’re anything like me, you will hate every single additional step to sign up, Asana show’s you the evidence of how you’ve already made progress and are almost done signing up. 

If you’re interested in psychology tricks like this one, check out Yes!: 50 Scientifically Proven Ways to Be Persuasive

Social graph: Quora (@quora) wants you to extend your social graph. When you receive a newsletter they’ll suggest people to follow after the content. 

Apple uses it’s own iOS symbols to invite people to it’s iPhone 5 (4S?) event. (Tuesday 4th, 10am, Infinite Loop 280, 1 more thing: iPhone)

Via and image credits The Loop.