Build and Maintain Consumer Trust
When used responsibly, email is a powerful tool for communicating with customers, strengthening relationships and driving ongoing revenue. Marketers should build trust over time by limiting the volume of email they send, not overpromising in subject lines, respecting consumers' email preferences and always quickly honoring unsubscribes — usually within 24 hours.

Test for Optimal Frequency
There is no magic number of emails that a marketer should send. The optimal number varies depending on the reason for communicating—e.g., news might be sent daily, discounts might be sent weekly or monthly, and product updates might only be sent quarterly or annually.
Test and analyze open rates, click-through rates, pass-along rates and conversion rates to help determine the most appropriate frequency for emailing your customer base.

Differentiate from Spam
It is no surprise that unsolicited promotional email is consumers' number-one concern about their email. It is critical for legitimate marketers to differentiate themselves from spam to avoid being automatically deleted or placed in users' bulk mail folder. Many marketers make it very clear at the beginning of an email how the consumer opted in to receive it. Others have tried tactics such as using their name in the subject line to emphasize to consumers which company it is from.

Test Your Subject Line
Not only should email marketers tailor their subject line based on the gender, age, location and preferences of consumers, where these are known, it is also important to measure the responses to varying subject lines across the entire audience. Email affords a much greater level of analysis than any other form of direct mail by enabling marketers to determine which recipients actually opened and read their mail, who passed it along to friends, and, of course, who acted upon it.

Use Email for Customer Service
As the preferred method of communication with companies, customers expect to receive customer service emails, such as purchase confirmation and shipping details. Marketers should consider automatic response emails as a highly cost-effective way to continue a dialog with a customer and emphasize the company's brand and messages.

Upsell Targeted Offers in Customer Service Emails
Although consumers expect to receive customer service communications from marketers, these messages should not be considered an obligation. Rather, they are an opportunity for companies to upsell even more targeted offerings to existing companies. Marketers should include offers in their customer service email, such as offer products that relate directly to purchases, or inform customers what other products have been bought by people that bought the same product as they did.

Referral marketing (sometimes called viral marketing) is when your readers promote your product/services for you.
Good content gets forwarded — to friends, to colleagues, to clients, and to anyone else a reader thinks might benefit. When that happens, not only do the people on the receiving end see the promotional sections of your newsletter, many of them decide to sign-up for future issues. That's good, that's exciting, that's what referral marketing is all about — your own readers doing your marketing for you. It costs you nothing and it is effective because someone else is promoting your products and services.

With e-newsletters referral marketing works in three main ways.
First those on your list forward a copy of the email they received from your business to their friends and colleagues. When you have tracking in place you can see this reflected in the statistics. For example our tracking showed this newsletter was forwarded from the reception desk of an organisation and as a result it was viewed hundreds of times. One of of clients received 1500 openings to their newsletter through the same method.

The second way referral marketing can work is that you have a 'forward to a colleague' link in your template - like we do in this newsletter. This means your readers can refer a friend to your newsletter - they can see what it is like and if they like what they are reading they can choose to be added to your mailing list.

The final way referral marketing works is when people refer their friends and colleagues to your website address. It is vital that you have sign up links to your newsletter clearly displayed on your home page and other pages on your website. It is also important that your website is geared for visitors so they can easily find and order what you have to offer.