"Spray and pray emails will never perform as well as tailored emails to particular contact segments," Turnbull says. He recommends segmentation for creating targeted email campaigns based on behavioral information or other contact data you know about each recipient. Doing so also helps to "determine&the right tactic for each segment," he adds. This can be done through A/B testing, which tracks the performance of two or more entirely different versions of an email message. "You can try a soft-sell message to your most active subscribers while offering a significant discount to those that are less active or haven't clicked lately," he explains.

While segmentation is effective, Turnbull notes that it is only as flexible as your contact data. He suggests that you look for ways to enrich contact data for purposes of targeting email campaigns by "appending contact data from other sources you have available-for example, CRM databases, website behavioral data, purchase history or other contact historical data."