What metrics do you use to define digital marketing success today? Clicks? Traffic? Followers? Leads? Sales? ROI? Notice what these metrics have in common: they all require some action on the part of the target, whether it’s a prospect or a customer. And how do you motivate an action? You use direct response communications. It’s as simple as that. Digital marketing is direct marketing. So why are we still seeing suboptimal digital communications in display, email, SEM, wherever. It’s a tragedy. If you follow these four principles, you’ll triple your digital communications results—and it doesn’t cost you a penny more.

Direct response communications are structured specifically to motivate an immediate response, which is why they are perfect for digital marketing communications. The structure relies on four elements.

Add an offer. The offer is the key motivator that overcome inertia and stimulates response. A strong offer can improve response rates by 300%. It doesn’t necessarily have to do with discounts or deals. In fact, in B2B, the most powerful offer is authoritative, educational information, packaged up in a report, a case study, a chart, a video—something that answers a question or solves a business problem. Make the offer the center of your messaging. Explain why they can’t live without it.

Make a strong call-to-action. The CTA is, in sales terminology, the “close”: where a rep asks for the order like “Click Here” and “Download Now.” Make it prominent, and make it persuasive. No more bland “More Information” buttons. Here’s a handy checklist of 75 CTA options to inspire you.

Prepare a dedicated landing page. This is where the real close takes place. Use the landing page to resell the offer, and capture the prospect’s information. Design the form to be filled out easily, asking for as little data as possible. If you already know some of the target’s data elements, as is likely with email communications, then prepopulate the webform. Whatever you do, don’t drive the respondent to your home page.

Test and improve. Continuous split testing is so easy in digital channels, you have no excuse not to take advantage. Test your audience segments, your offers, headlines, calls-to-action, design—everything. And keep testing, for continuous improvement. As Jan Brandt, the digital marketing pioneer who launched AOL practically single-handedly, used to say: “Do more of what works, and less of what doesn’t.”

After these four, there are plenty of other effective direct response principles you can apply. Improve your audience targeting. Use a friendly, personal tone. Add a sense of urgency. Focus on benefits over features. I could go on. But you’ll get 90% of the way there with the Big Four principles above. Then sit back and watch your digital marketing response rates soar.