How do you find the sweet spot? The best way is to monitor statistics from your email blast software. See how many recipients open your emails, how many click a link, and how many unsubscribe. (Pay attention to the type of recipient, too, as your open rates for loyal customers will be different from new prospects.) Learn what works, make changes, and test again.
Julie Ewald recommends moving away from sending generic content to your whole email list via e-blast entirely. With a little elbow grease, you can utilize segmentation and start sending off tailored messages to each of your lists with content that’s relevant, valuable, and designed to resonate with the kind of recipients that make up each segment.