Still More E-Mail Metrics
We don’t want to commit e-mail heresy. But are open rates and click-through rates the only metrics you can use for determining the success of your e-mail newsletter? They certainly are not. Others include the turn-off rate and the inbox delivery rate. Dig into them, and you will have a much more thorough sense of how your program is doing.
Turn-off Rate: Here’s something you really want to avoid: Angering customers with an e-mail. No matter how professionally you behave, there will inevitably be folks who will be angered by your e-mail and unsubscribe.
Unlike other metrics, turn-off rate is not easily conveyed in a calculation. It’s a theoretical ratio of the total number of e-mails sent to the number of recipients who took no action (no opens, clicks or sales). Think about it this way: If you send 1,000 messages and convert 20, that’s 2%. So how many of the other 98% have been turned off?
The key to turning off the fewest recipients possible is being careful not to perform the activities that most often raise their ire, such as:
*Sending e-m ail to an appended list—Appending your list is when you have some information on a person and you pay to have a data house supply you with additional information. In this case, let’s assume you have 10,000 postal address records and pay to have a third party supply you with the e-mail addresses of these folks. You then mail to them. You certainly did not get their permission to send them e-mail, even though they may be customers (and despite the fact that your action is well within the boundaries prescribed by federal CAN-SPAM legislation). Yet they are not expecting e-mail from you, and so it is likely you will be viewed as a spammer. You risk alienating good customers, generating complaints and getting blocked by ISPs. Try e-mailing them once with an acknowledge of your offline relationship and ask for permission to send additional newsletters. While using e-mail to ask for permission to e-mail is tricky, it can work for some marketers. We’d certainly recommend that this message be opt-in—meaning the recipient would need to take some action to continue receiving e-mail from you.
*Selling too hard, too fast—This is a typical mistake by first-time e-mail marketers. This is a typical mistake by first-time e-mail marketers. They get the addresses and then ram sales messages down the pipeline. While this tactic may generate a sales boost initially, you are sacrificing long-term customer relationships for short-term sales. Remember, in a well-crafted e-mail newsletter program, your audience signs up for relevant, quality content, not just ads.
*Sending large quantities of e-mail—Extra mailings may drive more sales, but don’t overdo it. A fast increase in sales may cost your dearly in the long run if you burn good relationships with subscribers, who have signed up for a newsletter and are now getting more than they bargained for.
Complaint Rate: In their ongoing battle to spare customers an inbox full of spam, ISPs in increasing numbers are providing a “This is spam” button. Clicking on this button usually removes the offending e-mail from the inbox and prevents any additional mail from the sender from getting delivered to that inbox. Many ISPs also use these complains as a factor to identify e-mail to block from everyone’s inbox. Therefore, the complaints of a few of your subscribers can prevent you from making it to the inbox of all your subscribers. When you consider that consumers don’t realize—or care—that their complaint blocks you from everyone else, or that their definition of spam may be liberal, it quickly becomes clear that you need to know how many people are hitting that button in response to your e-mail.
How do you find that out? Unfortunately, it’s not easy. Most of the major ISPs do not provide this information to marketers in any consistent or actionable way. The exception—and it’s a big one—is AOL. AOL has set up a free feedback loop service. Fill out the easy-to-use Feedback Loop (http://postmaster.info.aol.com/tools/fbl.html) and AOL will forward any mail that is reported as spam from subscribers using the AOL “This is spam” button. You must immediately remove these names from your list! This also makes it easy to calculate your AOL complaint rate: Just divide the number of complaints received over a set period of time by the number of AOL subscribers who you sent e-mails to during that same period of time. Other ISPs are considering a feedback loop, but as of press time, none had instituted one. In the absence of this data, AOL benchmarks are your best bet.
The biggest question many marketers ask is “What is an acceptable complaint rate?” None of the ISPs, including AOL, have a published threshold. And the truth is, it depends. Generally, complaint rate is factored against other troubling behavior to separate the good mailers from the bad.
As a general rule, you want to aim for less than 0.1%. Marketers really start to see problems at the 0.9% mark, but when other factors (such as high unknown users rates) are also a problem, the threshold for complaints may be lower.
You should also be measuring the rate of complaints that come directly to you. Again, divide the number of complaints that come through (remember to check all the e-mail boxes where customers might write) by the number of messages that you have sent. Assume that whatever number you arrive at, the number of people who hit “This is spam” is higher and make adjustments accordingly.
Inbox Delivery Rate: Unfortunately, a percentage of your messages will simply never get delivered to the customers’ inboxes due to overly aggressive spam filters. While spam filters are created with good intentions (they are supposed to keep the bad stuff out of customers’ inboxes so the inboxes are clean for personal, business and requested mail), they don’t always work properly in the eyes of publishers and marketers. In many cases, overly aggressive filtering is not your friend, as all the efforts you make to build your list and create appealing messages are wasted if the messages aren’t making it to the inbox.
One of the most frustrating aspects of blocked and filtered mail is that it frequently does not bounce back to you; it just gets deleted by the recipient’s service or shuttered off to a junk mail folder, never to be seen.
To determine if you have a blocking or filtering problem, look for unexplained drops in your open rate, especially if these instances come from the same ISPs. This is a sign that they may not be getting your e-mail. The best way to calculate your inbox deliver rate accurately is to seed every mailing with a statistically significant number of test names for every major ISP, then see what percentage of the mailings end up in the inbox.
Matt Blumberg is the driving force behind Return Path, an e-mail performance company. Collaborating with him on this project are his colleagues, e-mail strategists Stephanie A. Miller and Tami Monahan Forman. This article was excerpted from their new book, “Sign Me Up! A Marketer’s Guide to Creating E-mail Newsletters That Build Relationships and Boost Sales (iUniverse Inc., 2005) © 2005 Return Path, Inc. All rights reserved.
