A massive part of book marketing is persuasion, which is the process aimed at changing a person’s attitude or behavior towards an object (in this case, your book).
To change a reader’s attitude when book marketing, you can use both verbal (spoken or written) and non-verbal (visuals) tools to convey information and evoke feelings. 

This is why by using an array of video, text, content marketing, social media, and advertisements, you will find the best book sale improvements.

The two routes of persuading a reader to purchase your book

As a book marketer, there are two ways you can persuade a reader to buy your book. 

  1. The central route.
  2. The peripheral route.
The central route focuses on high involvement and engagements with your potential readers. This would include having high quality, thought-provoking conversation with your fans online. It is thought this route creates long-lasting relationships with your readers due to high levels of cognitive processing between yourself and them. 

On the flip side, the central route takes time and dedication to successfully persuade a reader to buy.
So, what sort of book marketing would be used on the central route of persuasion?
Social media and content marketing are great examples. 

Engage with your readers in comment sections and forums. Use online polls about thought-provoking topics relevant to your books. Create blog posts and videos that provide high-quality unique content and interesting ideas. This will create a long-lasting connection with your readers.
If you decide to invest in advertising, you could use comparative advertising, when going down the central route of persuasion; this is when you target books that are similar to your book and advertise to their readership. 
The other route of persuasion is the peripheral route, which features low involvement, with little thought and information processing. Your reader will be persuaded to purchase your book through repetitive learning, passive processing of visual cues, and holistic processing.
The peripheral route assumes subjective knowledge of your books from the reader, focusing on repetitive advertising and constant ongoing marketing campaigns.

In other words, rather than trying to understand and target a readership, you will use mass marketing, hoping that repetition is enough to convince people to buy your book.
Elaboration Likelihood Model
Credit: https://kpu.pressbooks.pub/introconsumerbehaviour/chapter/changing-attitudes/

Persuasive design for convincing readers to purchase your book

Persuasive design focuses on influencing readers’ behavior through characteristics within your book marketing.
Persuasive design is about creating experiences that convince users to take the desired action. 

These techniques are rooted in psychology, focusing on behavioral models and persuasive patterns. The key to persuasive design is to ensure your potential readers do not feel manipulated and that they are in control of their reading journey.
So how do you do this?
One great way is to focus on visual cues and appeals. 

If you can invoke a positive emotion from a reader (that they have already experienced in life), this may be pictorial or non-verbal cues (such as characteristics), then the person will be more likely to buy your product as they link this emotion to your book.

One common example of this is for T.V. commercials to use songs that would have been popular when the target audience were teenagers. The idea being that these songs will trigger positive emotions that the viewer will then link with the ad. 

Below is a great example of how Levi use music to create emotion:

The greater credibility and authority you can gain over your readers as a writer, the simpler job you will have in persuading readers along their path-to-purchase.
This said, if you are struggling to build your authority within your readership, there is another way around things and that is to use influencers, who have already gained traction with your target market.

This is why brands spend so much money getting celebrities to endorse their products, since the correct celebrity will give the brand a short cut to their potential audience. 

This also works at a smaller level, especially with tight-knit Internet communities. 
Marketing is all about trust, if your potential readers believe what you are saying they are more likely to listen and purchase your book.

This is why influencer marketing is so effective.
Think about things this way… if a stranger told you to buy one type of TV and your friend another, who would you be more likely to listen to? Your friend, why? Trust. 
As a book marketer, if you can find a popular author who writes within a similar genre to yourself and have them promote your book on their social media platform, this is literally gold dust. Just make sure their books are relevant to your own, so you attract and reach the desired readership.
There are two main persuasive motives to choose from when book marketing: promotion and prevention.
Promotion motivation focuses on encouraging hopes and aspirations, whereas prevention motivation prompts readers to avoid something negative.
Most fiction books would use promotion motivation as these types of book is all about escapism and exploring aspirations and issues. 

Whereas some non-fiction books, which explain how to do something, could use prevention motivation as they might be explaining how to avoid something negative. For example, a book that explains how to lose weight might focus on the health issues of being overweight. 
Potential readers can be influenced without realizing, it’s like a magic trick. 
The final persuasive design you can use as a book marketer is discounts for your books. 

Be aware, discounts can ruin the credibility of your book and some potential readers may wonder why you are offering a discount in the first place. I would recommend creating and using a mailing list to distribute discounts. This will hide the fact that you are offering a discount from the general public as well as reward your dedicated fans for joining your mailing list and community.
To find out more about email marketing, visit here (https://proactivewriter.com/blog/email-marketing-for-authors).

Final Thoughts

Convincing a reader to buy a book is all about creating experiences that will lead to people taking your desired action.
Visual cues can include verbal and non-verbal aids, which should vary and be optimized across all digital devices.
Use social media as a further tool to persuade readers to purchase your books but avoid making a potential reader feel manipulated as this will harm your reputation and credibility. 

Furthermore, avoid over-promoting and persuading when selling your book, keeping track of your campaigns and techniques to make sure that you do not overdo it.