Increase email click-through rates 61% with specific, prominent calls to action

Designing email for mobile is important, as mobile accounts for half of email opens these days. But optmizing your call to action is the key to increasing open rates.

Here's a case study from the Direct Marketing Association (DMA) about how a recent redesign increased click through rates by 61%:

  http://dmaemailblog.com/2013/09/06/email-design-change-driving-a-61-click-increase