Performance metrics are critical to assess the success of email marketing. Much time and attention is spent analyzing open rates, click-throughs, and conversion rates; yet there is an underlying metric which has a significant impact on all performance: subscriber trust.When email marketing is built around trust, subscribers are more likely to opt in and not only engage with messages, but also convert and remain loyal to a brand. But what does it take to create subscriber trust in an era of data breaches and increasing email privacy legislation?