In order to engage customers, retailers must shift from a linear marketing approach of one-way communication to a value exchange model of mutual dialogue and benefit-sharing between provider and consumer.[21] Exchanges are more non-linear, free flowing, and both one-to-many or one-on-one.[5] The spread of information and awareness can occur across numerous channels, such as the blogosphere, YouTube, Facebook, Instagram, Snapchat, Pinterest, and a variety of other platforms. Online communities and social networks allow individuals to easily create content and publicly publish their opinions, experiences, and thoughts and feelings about many topics and products, hyper-accelerating the diffusion of information.[22] 

Even though this falls into just one of the myriad of elements in the 20 portion of the 40/40/20 rule, it is arguably the most important. Nothing will get your piece of direct mail marketing throw into the trash bin more quickly than a glaring typo, a noticeable formatting issue, or an overall poor print quality. If you’re writing the copy, be sure to not only proof it yourself but also have some of your more linguistically-inclined friends and colleagues give it a once over, not only for grammatical and punctuation mistakes but for overall ease of reading and flow. Don’t be afraid to seek as many trusted opinions as possible, and be sure to have thick skin to prepare for any constructive criticisms.
Use personalization. Personalizing the content of your emails (depending on your segment from Chapter 3) will make it infinitely more relevant and valuable to them. Personalization is so much more than inserting your subscriber’s first name into the email. You need to tailor the actual content of the email to address their needs. For instance, an online retailer will find it much more valuable to read an email with the subject line, “How to build backlinks to your eCommerce store” than just a generic subject line, “How to build backlinks.”
Julie Ewald recommends moving away from sending generic content to your whole email list  via e-blast entirely. With a little elbow grease, you can utilize segmentation and start sending off tailored messages to each of your lists with content that’s relevant, valuable, and designed to resonate with the kind of recipients that make up each segment.