It only makes sense to invest more in the marketing efforts that produce the greatest return on investment (ROI).

Luckily, companies are three times as likely to see a higher ROI on inbound/content marketing campaigns than outbound, according to Hubspot’s 2015 State of Inbound. This makes perfect sense since the goal of content marketing is to attract new customers by creating and sharing valuable content with your target audience.

By answering common questions that your target audience is asking, you make it easy for them to find you organically. Then, they build trust in you and your expertise. With a clear, defined strategy to turn those new readers — or "leads" — into customers, you can close more and increase your ROI.

One of the best ways to convert your leads is by using email marketing. Discover why email marketing still matters, and improve your open and click through rate, too.

Data proves email marketing still works in 2015

  • The average ROI for every dollar spent on email marketing is $44.25, according to ExactTarget.
  • Email marketing offers a 17 percent higher conversion rate than social media. Plus, those who buy because of email marketing spend 17 percent more, found McKinsey & Company.
  • Companies using email to nurture and convert leads generate 50 percent more sales-ready leads at a 33 percent lower cost, says Hubspot.
  • 4.68 percent of shoppers have a made an online purchase because of a marketing email, according to the Direct Marketing Association.
  • 5.95 percent of those who sign up for your company's newsletter consider your brand emails useful, reported Salesforce. And 70 percent of people say they always open emails from their favorite brands, found ExactTarget.

Easy ways to improve open and click rates of brand emails

Email marketing still does work. Now, the trick is to make your brand's marketing emails stand out from the 121 emails the average person gets a day.

Here are simple ways to get more of your brand's emails opened:

  • Shorter subject lines: Subject lines with a mere three words are opened the most. After that, the more words you add, the less opens you get. Another secret key to success is adding the phrase "Re:" to applicable email subject lines to boost the open rate, according to ContactMonkey.
  • Add social share buttons: Emails with social share buttons increase click-through rates (CTR) by an incredible 158 percent, says Nonprofit Hub. Not only does this boost your CTR, but by giving customers the opportunity to share your branded content, more people can discover your brand.
  • Tout discounts: 72 percent of customers sign up for brand emails because they want discounts, according to BlueHornet. Give your customers want they want by delivering a discount when they sign up. Then, keep their interest by sending promo codes around holidays and at least once a quarter.
  • Make it mobile. 66 percent of emails are opened on a smartphone or table, says Movable Ink. And, 69 percent of people who open an email not optimized for mobile on their smartphone instantly delete it, according to Litmus. Optimizing your emails for mobile gets them opened and gets the content read, too.
  • Get personal: Personalized marketing emails have a 29 percent higher open rate and 41 percent higher click rate than generic emails, found Experian. Addressing the email using the sender name is an easy place to start. From there, personalize the content you're sending by segmenting your email marketing lists.