The more you know about your customers, the better you can engage them. Like with any relationship, one of the best ways to get to know someone is by asking questions. That's why you should be sending subscribers surveys.

Surveys provide invaluable information to help you better understand and target your audience. There's no doubt that surveys are a powerful tool for any business or marketer, so the question becomes how to make them worth the subscribers' time. Here are six ways you can encourage your customers to complete a survey.