It remains one of the most productive for countless businesses. In fact, according to campaign monitor, for every dollar spent, email marketing generates $38 in revenue. Given the importance of email to many businesses' businesses, it's no surprise that the use of ai, and machine learning (ml) in particular, is growing among marketers. By e-mail. Here's a look at how ai is applied to email marketing. Multivariate and a/b testing sophisticated email marketers have used multivariate and a/b testing for years, but ai and ml allow marketers to perform testing in ways that weren't possible before. A growing number of technology vendors are offering ai and ml-based testing platforms that allow marketers to create more robust tests, identify trends and make predictions faster, a Nd identify subtle differences between tests that might go unnoticed without the help of ai. Some platforms, like optimail, even give email marketers the company mailing list ability to optimize their campaigns on the fly, eliminating the risk of lost revenue while running tests. Subject line and copy optimization which subject lines and email copy will produce the best results? For years, marketers have struggled to take the guesswork out of crafting the perfect email — with little success. Now, thanks to platforms offered by companies such as phrasee and persado, email marketers can let ai determine the subject lines, body text, and calls to action that recipients are most likely to respond. Machine learning allows these platforms to learn what resonates best with a specific marketer's audience. These platforms then use natural language technology to create subject lines, body text, and calls to action that not only sound like they were written by a human, but are consistent with the language generally used by the brand. The result? According to phrasee, its ai-generated subject lines outperform human-written subject lines more than 95% of the time, and persado goes so far as to claim that its "Cognitive content" outperforms human-generated content. Man 100% of the time. While it's hard to resist these kinds of claims, even email marketers who aren't yet comfortable letting ai take the wheel and drive have the opportunity to take advantage of the technology.