Historically, it has been difficult to measure the effectiveness of marketing campaigns because target markets cannot be adequately defined. Email marketing carries the benefit of allowing marketers to identify returns on investment and measure and improve efficiency. Email marketing allows marketers to see feedback from users in real time, and to monitor how effective their campaign is in achieving market penetration, revealing a communication channel's scope. At the same time, however, it also means that the more personal nature of certain advertising methods, such as television advertisements, cannot be captured.
Focus on the reader first. You should always write your emails to address the needs of your subscribers, not yours. Offer ways to solve their problems, don’t simply talk about your products and how great they are. (This is a part that so many companies get wrong.) Ask yourself, what are the biggest pain points/struggles for my subscribers? How can I solve their current problem in this email?
When you meet people face to face for any reason, ask for their business card. Offer yours. Set a glass bowl on the counter in your store or the reception desk in your office, and ask visitors to drop their cards in it. Offer some incentive to do so — a free product or service, gift card, etc. Use your own business cards to further drum up emails; add an offer on the back of your card that encourages people to sign up to receive your emails.
Email marketing is the act of sending a commercial message, typically to a group of people, using email. In its broadest sense, every email sent to a potential or current customer could be considered email marketing. It usually involves using email to send advertisements, request business, or solicit sales or donations, and is meant to build loyalty, trust, or brand awareness. Marketing emails can be sent to a purchased lead list or a current customer database. The term usually refers to sending email messages with the purpose of enhancing a merchant's relationship with current or previous customers, encouraging customer loyalty and repeat business, acquiring new customers or convincing current customers to purchase something immediately, and sharing third-party ads.
Most of the article really talks about how to successfully get an email of a person who has already landed on your landing page/podcast page/affiliate/blog etc. but how to get those people there in the first place is a bigger challenge. Also, one of the ways you can include in your list is by offering free tools/widgets. For example, OpenSiteExplorer by Moz is a great example. Evergreen and very useful for the target audience.