Editor’s Note: This is the second in a two-part series.

Measurement is the Holy Grail of marketing. A savvy marketer would naturally prefer to invest his dollar in a strategy with a measurable return on investment versus one without.

Sixty percent of marketers report that email marketing produced a measurable return on investment according to MarketingSherpa’s 2013 Email Marketing Benchmark Survey of more than 1,000 marketing pros across the country.

Not surprisingly, numerous studies also cite that businesses are increasing their investment in email marketing in 2014.

To produce a strong return on your email marketing investment, first deliver on these fundamentals:

• Properly growing your email database

• Writing an engaging-yet-succinct subject line

• Designing with mobile in mind.

With that foundation in place, consider these advanced strategies for improving your return.

Professional email platforms have offered “trigger” capabilities for the last few years, allowing you to automatically send lightly personalized emails to customers based on an event that has occurred.

Consider more sophisticated triggers than the traditional welcome or thank you email after a new subscriber signs up or a customer places an order.

Try sending a request for a customer review 30 days after purchase or recommending an add-on product or service to accompany a recent purchase.

Require site that visitors wanting access to premium content – such as white papers or industry research – provide you with basic contact information including an email address.

Shortly after the download, send a trigger email offering additional related content to continue the conversation.

Automatically send emails to prospects when they move into each new step in the sales process.

Consider a question-and-answer format addressing a common concern at that stage in the sales cycle, such as “I bet you’re wondering how our service stacks up against the competition.”

Today’s consumer relies heavily on social proof – what other consumers have to say about your brand – before making a purchase. With this knowledge, expedite the sales cycle by including in your email campaigns customer reviews or positive customer tweets or Facebook posts.

Ensure your campaigns have a single call to action. Any more will cause indecision and a delayed response, which generally lowers response rates.

Email marketing is one of the easiest of all marketing channels to test. With each email campaign, divide your audience in half and test one element against another.

Consider testing two subject lines, two headlines, two different distribution days of week or times, or two different “from” names.

In fact, the ease with which you can test one email marketing strategy against another allows you to break all the so-called email-marketing rules and determine what works uniquely for your brand.

Lori Turner-Wilson is an award-winning columnist and managing partner of RedRover Sales & Marketing, www.redrovercompany.com, with offices in Memphis and Nashville. You can follow RedRover on Twitter (@redrovercompany and @loriturner) and Facebook (facebook.com/redrovercompany).