Effective marketing boils down to this: Find an audience, figure out what they need or want, and then deliver it. Email is one of the best mediums to help you do just that. And it isn’t always about selling them a product. In fact, that isn’t at all where you want to start.
First you want to build a relationship with your readers. You want them to get to know you. You want to help them out so they start to like you and trust you. Only then will you be able to make an offer and have them pull out their wallet and buy it.