According to the 2007 Email Marketing Benchmark Guide" survey conducted by MarketingSherpa, you should test the words you write first. That's because the e-mail tests that give the highest ROI are about copy performance.
Landing-page copy tests scored best. An estimated 43.2 percent of those surveyed gave it a "high ROI" rating. The A/B testing of e-mail offers ranked second (40.7 percent). Subject-line tests were a close third (40 percent).
But don't overlook the importance of graphic design. An estimated 34.4 percent of e-mail marketers said A/B testing the e-mail creative (images and formatting) delivers a high ROI. And 33.6 percent gave the same rating to the landing-page creative test. So testing design elements can make a big difference to your bottom line, too.
You may be tempted to ditch e-mail testing to invest in sexy Web 2.0 technologies instead. Don't--e-mail is too valuable. In fact, Marketing-Sherpa reported that 40 percent of B2C marketers and 35.6 percent of B2B marketers see e-mail's impact as increasing significantly. That may be surprising news--but it's certainly good news, too.