Also important for the growth of your business is that you’re always adding new customers. That’s what’s going to grow your revenues and make your business profitable. You can never stop generating new leads, because old leads will fall off the list or start ignoring your emails… and many will never buy. So it’s key to not let your list stagnate: Keep it fresh with an infusion of new names, all of whom are potential buyers.
There are tons of websites and publishers out there that cater to your audience -- and larger portions of it. Guest blogging for these websites helps you expand your contact list to this audience. When creating content as a guest blogger for another website, include a call-to-action, as well as a link in you author byline, for readers to subscribe to your site's blog or email newsletter.
It’s a best practice to ask the referrer not only for a friend’s email address, but also for a full name so that the message is personalized. Most important, remember to add the referee’s full name to the email as well. By referencing whom the email content was recommended by, you gain instant credibility and will attain much higher conversion rates.
For effective and actionable results, you should do A/B tests, which test two (or more) different approaches. For example, you could send half of your list one subject line, and an alternate subject line to the other half. You could also A/B test the two approaches with a small subset of your list, then send the winning headline to the rest of the list.