March 31, 2015
Case Study

Email Marketing: 'Go Green' campaign lifts revenue $30K for bookstore chain

SUMMARY: Direct mail is a costly marketing campaign strategy, both when it comes to money and environmental impact. So how can a retailer persuade subscribers who have been subscribed to both direct mail and email communications to make the switch to email only?

Learn how Half Price Books, a brick-and-mortar and online new and used book retailer, crafted a two-part campaign targeted at direct mail subscribers to convert them to email-only subscribers. This campaign, which had clickthrough rates as high as 44%, netted $30,000 in revenue from a coupon offer included in the incentive for subscribers to make the switch.
by Erin Hogg, Reporter

Half Price Books is like the Trader Joe's or Whole Foods of book sellers. As the nation's largest family-owned new and used bookstore chain, Half Price Books operates 121 stores in the U.S. in 16 states.

The business was founded in Dallas in 1972 with a mission to conserve the environment as well as promote literacy.

"We recycle books, and we keep books in circulation; that's important to us. We have a commitment to preserving the environment," said Kathy Doyle Thomas, Executive Vice President, Chief Strategy Officer, Half Price Books.


Customers of Half Price Books are very active online — sharing what books they have read, finding new books to enjoy and serving as brand ambassadors. Customers of Half Price Books can stop in at a brick-and-mortar location or order books online through the brand website.

The culture that the brand fosters is easy-going and laid back with a focus on going green.

"Our employees wear T-shirts, and it's pretty laid back and comfortable and casual. We build our own shelves, so we have a lot of wood in the stores. We use recycled paint. We're kind of like do-it-yourself, and we use all green products. It’s the mission of the company, and we try to live our mission," Doyle Thomas said.


Like any other business, Half Price Books needs to save on costs whenever possible. While the brand lives by a green lifestyle, it does send direct mail pieces to its list as well as email marketing.

Printed pieces are sent three times a year to customers, and many of these recipients enjoy receiving printed notices in the mail.

However, in an effort to save on costs and be as green and environmentally-friendly as possible, the team is always looking for ways to achieve both goals.

In addition, Doyle Thomas and the team also wanted to eliminate duplications: Some customers were receiving both printed mail as well as digital coupons online.

Half Price Books needed to turn some of those print and email subscribers to email-only subscribers by leveraging the value of what the email program could offer, while embracing the positive impact eliminating printed mail would have on the environment.


The team turned to email as a channel to launch the "Go Green" campaign, with the first email sent on Jan. 8, 2015.

They picked the beginning of the year to encourage subscribers to switch to email-only preferences, which fit in with the theme of a new year — a time to do good and make positive changes.

In addition, the timing was also chosen because of a large mailer scheduled in the beginning of March, so subscribers would have enough time to opt-out.

Step #1. Plan out campaign

January 2015 was a busy month for Half Price Books in terms of marketing promotions. When the team decided to run the Go Green campaign in January to meet the deadline for the print mail piece in March, they also needed to prioritize when that campaign would run. The team was planning on running a "Resolve to Read" campaign, to promote a New Year's resolution to read more, as well as a campaign to encourage customers to come in and sell books to the brand.

"It was a little bit of a puzzle to organize. Where do we fit this in the perfect way where it's going to stand out, it's going to resonate with customers and not get mixed up with some of the other things we had to say?" Jason Permenter, Email Marketing Coordinator, Half Price Books, said.

As Doyle Thomas explained, balancing the timing for campaigns can be a challenge because every marketing campaign is important for various reasons.

"I think that's tough because every marketing team has to juggle and prioritize the email blasts. Everyone's says, 'Oh, they're cheap to do. Let's do them all!' And you can try to do them all, but how effective will all of them be?" she said.

The Go Green campaign also stemmed from an older campaign called "Become Green," in which Half Price Books donates five cents to environmental causes for every customer who declines a bag in-store at checkout.

"But what I love about the Go Green campaign is that's a green message that we've used in a lot of different areas, and we're able to implement it into this email campaign," she said.

Permenter reiterated this campaign fit with the brand's audience. "It wasn't really coming out of left field for us to come out and say this. This was just an extension of a campaign that we've run in completely different ways in the past, and we're able to apply technically here."

Once the goal of getting subscribers to switch from direct mail to email communications was established, the teams began to brainstorm what the email copy would consist of.

Permenter believed that many subscribers of the direct mail didn’t understand the differences between the postal and email program. As he explained, the campaigns for both are very similar, with very little differences in the offers.

He wanted to emphasize to subscribers the value of selecting an email-only subscribership:
  • Email subscribers get notifications of new arrivals and events

  • Email subscribers receive the same coupons and discounts plus additional ones direct mail recipients miss

  • Email reaps the benefit of reducing the amount of paper to help the environment

From there, the creative team looked at methods to spice up the email's design and make it a memorable message that subscribers would act on. Animation was implemented via a GIF, turning the email's red theme to green. Doyle Thomas explained this was a strategic and fun way to get the message across.

View the Creative Sample

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Choose the right channel

Because the Go Green campaign's goal was to turn print and email subscribers to email-only subscribers, the team made sure to isolate the campaign to the email channel only.

The team wanted to be able to test and optimize the campaign in email and didn't want to have a coupon floating around on the brand's social media, which has more than 20,000 fans on Facebook.

"We wanted a benefit to our email list. The coupon is like we're doing something special for them," Doyle Thomas said.

Step #2. Test email campaign

Half Price Books A/B tests its email campaigns in real-time to ensure the most effective message is sent out to the majority of the list.

Within the email platform, the team sets up an A/B subject line tests with 40% of the list — 20% receiving the control and 20% receiving a treatment. Then, two to three hours after the send, when the team has some data on which subject line performed better, the winner email is sent to the remaining 60% of the list.

In the first send for the Go Green campaign included a subject line, which was "very on-brand, very consistent with the messaging in the email," as Permenter explained.

The team then tested including the customer's first name: [Name,] want to switch?

Including the customer's name in the subject line performed better, and as Permenter explained, he has seen that posing subject lines in the form of a question entices more opens for Half Price Books.

First name personalization generally performs well, but Permenter is careful to only use that tactic when it's appropriate and relevant, not for every sales-driven email.

"The goal there, though, is to attract two different types of people: the types of people who are going to respond to a solely green message and are attached to that green buzzword and the type of person who wants to be communicated with directly," Permenter explained.

Step #3. Send second email with coupon incentive

To entice subscribers who did not take action in the first email of the campaign, a second send was sent on January 22, keeping the Go Green campaign theme but adding in a coupon incentive when a subscriber opted for email only.

"We wanted to entice them with a coupon, and we even translated that up to the subject line of, 'If you switch right now, you'll get some instant savings that you can use right away.' Maybe that type of person would respond as opposed to just going on the green message on its own," Permenter explained.

View the Creative Sample

Click here to see the full version of this creative sample

This coupon offer was $5 off a $25 purchase once the subscriber opted for email-only communication preferences.

Doyle Thomas added that, like every brand, Half Price Books needs to use coupon incentives wisely as to not to over-send promotional messaging and cut into sales margins.

When sending promotions, the team also avoids using urgency in the beginning of a campaign and saves deadline messaging (i.e., five-day sale) toward the end of the campaign.

"If it's a five-day sale — that's five days from now — it's not always going to be as urgent as it is a last day or ends tomorrow or things like that. We'll typically structure an ad campaign like that of kind of a softer approach at first, kind of get their interest," Permenter said. "By the end of it, it's really into a hard sale, more of an urgency and get them in right before something is over.

Step #4. Conduct post-mortem analysis

Permenter reviews and analyzes the performance of email campaigns each week and communicates results and achievements with Doyle Thomas and the team.

They look at high-level tactics and approaches and share those across the board as there are lessons learned from email campaign results that can be shared throughout the company.

Clickthrough and open rates are key metrics for Half Price Books' marketing team, and those were also reported to the rest of the team for this campaign.

An unexpected benefit that arose from this campaign was that the team was able to clean up the subscriber list and preferences of errors.

Some subscribers had inaccurate information, and this allowed them to update it in the system for better communications.

"I constantly want to have everything as perfect as I can have it be, in terms of information and settings. It never will be perfect, but it's always good to get it cleaned up as much as you can, so that we can kind of get that maximum efficiency of what we're saying and when and how much of it we're saying and all of those different things," Permenter said.

The timing of this campaign also proved to be an advantage for the brand, as a new redesign of the Half Price Books website is scheduled to launch in March. Having more of a spotlight put on the email program is helping to elevate the digital presence of the brand.


"Everything we do is obviously for our customers, and we want to target our messaging exactly around what they want to know, what they want to hear, what they want to see … we definitely leverage that feedback and information," Permenter said.

The Go Green campaign successfully converted many subscribers to switch to email-only preferences. More than $40,000 was saved for Half Price Books by reducing overlapping communication. The coupon also netted an additional $30,000 in sales.

For the first email, the team saw:

Subject Line: [Customer Name], want to switch?
Open Rate: 33.47%
Clickthrough Rate: 44.07%

The results for the second email with the coupon included:

Subject Line: Instant savings when you switch …
Open Rate: 28.64%
Clickthrough Rate: 38.67%

Email marketing has also led to faster and more accurate customer behavior discoveries versus direct mail.

"This is instantaneous, and it keeps us on our toes ... I think that's what marketing teams have to be able to do with campaigns. All of ours is in-house, and everyone on the team is constantly online or on their phone or seeing concerns through Facebook," Doyle Thomas said.

While this campaign proved to be successful for the brand and set the bar high, the team at Half Price Books will strive to do even better in campaigns to come, continually testing and optimizing their efforts along the way.

"There are always things that you could do better … When you're a victim of a great, successful campaign, the first thing is, 'Let's do it again! Let's keep doing it!' But then, when does it get to the point of no return?" she advised.

Creative Samples

  1. First email

  2. Second email


Half Price Books

Related Resources

Green Marketing: How to tap into a $3.5 trillion market

Green Marketing 101: How and why you should be interested

Marketing Research Chart: How do marketers perceive the ROI of email marketing?

Case Study: Creativity vs. clarity in email subject lines

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