Do you know how to persuade? It’s a critical skill for an email marketer. Perhaps the most critical.“You’ve created your campaign and attended to all the details of identifying your audience, created your offer, and toiled for hours and hours, honing copywriting and design,” writes Gary Hennerberg at [Target Marketing](http://www.targetmarketingmag.com/post/17-principles-persuasion-direct-marketing-style/all/). “But in the end, the tipping point for your success likely stems from the degree to which you emotionally persuade an individual to take action.”In his groundbreaking 1984 book, “[Influence: The Psychology of Persuasion](https://www.amazon.com/Influence-Psychology-Persuasion-Robert-Cialdini/dp/006124189X/ref=sr_1_1?ie=UTF8&qid=1515170769&sr=8-1&keywords=influence+the+power+of+persuasion),” Dr. Robert Cialdini identified what he termed “The Six Principles of Persuasion”: reciprocity, commitment/consistency, social proof, authority, liking and scarcity. He was onto something important: his book has sold more than three million copies and been translated into 30 languages.If you haven’t been putting Cialdini’s principles to work in your email marketing, now is a good time to start. Read on to learn how you can leverage them in your campaigns.**Reciprocity**“Reciprocity is the obligation to give once you receive,” writes Mark Brown at [Emailaudience](http://www.emailaudience.com/convert-reciprocity-to-your-email-marketing/),Brown illustrates the power of reciprocity by citing a study linking mints that accompanied diners’ checks with higher tips. “The waiters in the experiments enjoyed double the tip amount for one mint (3%), quadruple the amount for two mints (14%) and went as high as 23% when the waiter provided extra gifts unexpectedly,” he writes.The bottom line: “In every email that asks users to take an action – whether it be clicking on a link, buying a product or sharing information – you should offer a small gift or offering. These gifts can be downloads, discounts or even entertaining videos, however, they should be seen as having some kind of inherent value in order to be effective.”**Commitment/consistency**This principle posits that once people make a commitment, they behave in a manner consistent with that commitment.Asking recipients to sign-up to receive free content is an example of gaining commitment. Once they do that, they are very likely to take the subsequent steps needed to obtain your offer.“You’re persuading people to commit to your content, so that they start behaving in alignment with their choice of committing to you,” writes [Neil Patel.](https://neilpatel.com/blog/how-to-use-cialdinis-principles-of-persuasion-to-improve-your-content-marketing-strategy/) “The returns garnered by the commitment and consistency principle could be something as subtle as liking and sharing your content on social media or something as large as following your CTAs.”**Social proof**Social proof drives conformity by compelling people to behave in alignment with the actions of others. Social proof gets results. It’s why email marketers use testimonials, endorsements, awards, product reviews, press coverage, and other forms of validation in their messages.“Put simply, people trust people, not ads or self-promotion,” writes Daniel Kohn on the [Kissmetrics blog](https://blog.kissmetrics.com/the-social-email/). “We want to see or hear or read about others using, enjoying, and succeeding with a product or service before committing to it ourselves.”**Authority**“The principle of authority says most of us realize we can’t be experts at everything,” write Jacob McMillen at [The Daily Egg](https://www.crazyegg.com/blog/psychology-of-persuasion/). “Our best bet is to rely on the testimony of experts. Accordingly, we allow experts and those considered the ‘authority’ on any given topic to influence us.“You can put the principle of authority to work in email marketing by citing professionals to back up any claims you make, by pointing to research conducted on your product or service by prestigious organizations and by showcasing awards and other recognition your company has earned.**Liking**“It’s hard to say ‘no’ to someone we like or consider a friend, because we want to make a good impression and preserve the friendship,” writes Alexis Rodrigo at [Vero](https://www.getvero.com/resources/weapons-of-persuasion/).When it comes to leveraging this principle in email marketing, “The key is to get your subscribers to like you in the first place,” Rodrigo advises.“To start, your emails should sound human. Write conversationally – think business conversation, not street talk – avoiding jargon and legalese.”More tips: “Show the human side to your company or organization. Let subscribers know who’s writing to them, and show an agreeable photo of the author. Get the people who make up your business to share who they are through personal anecdotes or stories that relate to the rest of your email.”**Scarcity**“The feeling of being in competition for scarce resources has powerfully motivating properties,” [Cialdini wrote](https://brandongaille.com/44-breathtaking-robert-b-cialdini-quotes/).“Scarcity triggers an emotion response because we find it hard to resist wanting things that are scarce,” writes Sarah Jamieson at [Persuasionworks](http://www.persuasionworks.com/persuasion-psychology/scarcity-and-exclusivity.htm). “Scarcity also increases desire.If we know we can’t have something, we want it even more.”Jamieson suggests email marketers leverage the persuasive power of scarcity by stressing that quantities are limited, that the product is only available to members of an “exclusive” group, or that a deadline is looming.