If explicit data are what users submit on your forms, implicit data are how they actually behave on your website. For example, your customers might say their data's challenge is lead generation in your forms. But when you look at your analytics closely, your articles about blogging or content creation garners the most traffic instead of lead generation. These people will be more receptive to your emails about blogging compared to sending it to the rest of your email list who may or may not be interested in blogging. What people say and what people do are often different. That is why combining both explicit and implicit data when you segment your list will only make your marketing campaigns more effective.