There are two kinds of people in this world – those who A/B test their emails, and those who don’t. The reasons why we don’t always A/B test are very defensible; it requires extra time from already thin resources, the focus is on getting the some of the email out and not necessarily read, and even without A/B testing email has outstanding ROI. I empathize with all of these.

Still, wouldn’t it be nice to enjoy some of the performance benefits of A/B testing without taking the extra step? It would, and you can. It is possible to improve your open rates even when you are not A/B testing. Here’s how:

1. Study Subject Lines by Open Rate: A/B testing works best because it isolates a single variable for a clean analysis. If you send two emails, each to a randomly selected half of your list, at the same time and with the exact same creative, design, copy and call-to-action, changing only the subject line, you can confidently attribute any delta in performance to the subject lines. As I said, that’s the cleanest analysis, but it isn’t the only one. Try running a report of all your emails ranked by open rate. (In Real Magnet you can run this very report as “Highest/Lowest Opened Subject Lines.”) Study the list of your top performers, looking for points of commonality. Does an offer appear frequently? A number or a % sign? Do many end with a question mark? Does length seem important? Now do the same thing with your worst performers. You won’t learn with the same certainty as you do with A/B testing, but there are conclusions to be drawn in that data. At the very least, you should be able to come away with some new hypotheses to work into future subject lines.

2. Segment More: When you run your reports on top performing subject lines, look also at your list size. I’d bet my sender score that as a rule, the messages you are sending to smaller lists have higher open rates. There are a few reasons for this, and all of them have to do with relevance. A smaller list means narrower segmenting, allowing you to lead with a subject line that has a greater chance of being relevant to your target audience. So if you want higher open rates, segment more – break your big list into smaller lists and modify your creative or at least your subject line to better reflect your audience. For example, if you are sending a conference promotion to your entire list your subject line might read, “Keynotes and Workshops Announced for the Annual Meeting.” But if you are sending the same message to a segment of people who attending the Marketing Track sessions last year you might switch the subject line to something that will get their attention better, like “ABC Company CMO To Keynote On Mobile Marketing at Annual Meeting.” The rest of the message can be the same, but you’ve used the subject line to telegraph the content a particular segment will find most appealing.

3. Reap Additional Segmenting Benefits: When you segment, you are not only able to use more targeted subject lines; you also end up sending more messages, and generating more data points about – generally – what aspects of a subject line boost performance to you. So by increasing your segmenting in Step 2 (above), you’re boosting the learning you can extract from Step 1 (above above). Improve your performance by getting smarter, by improving your performance, by getting smarter.

4. Experiment with the Unexpected: Now that you’re looking for how differences in your subject lines impact open rate, make them easier to spot with bigger changes. Try some subject lines that are clear departures from your usual practice. Use a 3-word subject line, change your tone, remove a regular prefix like “Newsletter”. The more variation you can include the better, because only by doing something different can you expect your results to change.