I think it is fair to say that the performing arts industry is pretty far behind the email marketing curve, operating with email 1.0 technology. New technologies exist to tie email into e-commerce on email 2.0. Think of email marketing as a conversion funnel where the first step is a user opening an email and the final step is a user purchasing a ticket on your website. Most email programs that arts organizations employ stop tracking a user once they click on a link in an email. All they track are email open rates and click-through. New technologies can track much further, following users all the way to purchase or cart abandonment. Email 2.0 systems can be set to automatically send follow-up messages based on user browsing and purchasing behavior, which can ultimately lead to major increases in sales.
For example, say you send your weekly or monthly newsletter that includes two items: the first about a new production announcing tickets are on sale and a second that includes a donation appeal. In email 1.0, you can see through the analytics that your email achieved an 18% open rate and a 2% click through rate. But with email 2.0, you can see the pages of your website each recipient visited and whether users purchased or not. In the email program users are grouped into openers, clickers, browsers, and buyers. From that you can set the system up to automatically send a triggered email to those who may have visited a production page but did not purchase, for example. From there it can trigger a third email to send a few days later to those that visited the production page a second time but did not purchase; but this time perhaps include an offer to entice them to close the sale. For the donation item you can set it up to do the same. If a user clicked through but did not donate, you can trigger it to send another email with more information about the benefits of giving tied to the page they visited. If they still don't give, it can send an additional appeal and so on. This is called email re-targeting.
You can also set up cascades based on initial email sign-ups. So when a user signs up for your email list online they get an immediate welcome message. Automatically, a few days later, they get a second message asking them to follow your organization on Facebook. Perhaps a week later they get an offer to come to a performance if they have not yet purchased a ticket.
I have found that the costs for these advanced tools are the same or even less on a per-email basis than most email programs that arts organizations employ. I am personally very excited about these technologies and think they offer a tremendous upside to arts organizations. I am working with a few clients on beginning to use these tools and will report back.