When authors promote themselves, they automatically promote their writing. It's a core part of book publicity, and since promotional tours after a book launch involve authors, the two go hand in hand. The concepts of personal branding or personality cultivation receive much attention because it usually takes more than writing a book to earn a living. When you're well known and respected by a target audience, you can sell them many things, your speaking appearances and advice included. Writing a book instantly earns you respect and stature, and author branding leverages it to further yourself and your career.
When you write a successful book, often your first or second one, your name becomes well-known to readers and the media. It makes you a brand with an identity because people associate a specific genre of book or type of expertise with your name. For example, the author of one of the 20th century's most famous baby books, Dr. Spock, became a household name. He had a solid personal brand that meant people were interested in a wide range of things he wrote about babies and child development. Few writers achieve that international notoriety, but even lesser versions are beneficial.
From the start, successful authors have a clear target audience in mind and focus on being discovered by them. Podcasts and blogs are the newer ways to reach people and are pretty compelling. When you find an audience closely aligned with your target group, you want to get them in hopes they will ultimately become part of your audience. That's why carefully selecting interview appearances, speaking platforms, and guest posting opportunities is crucial. A well-developed plan that guides your outreach (or the outreach your publicist will make) is always more productive—you want to accomplish your goals.
If you're an author doing a publicity tour with a book, virtually or in person, think long-term about building relationships with the media. There's no reason your conversations with them are limited to one time about your book. You'll be called on again if you're helpful and knowledgeable and provide quotes and comments that work well in their stories or video segments. Becoming a frequent and trusted media source is an excellent way to build visibility. Over time, you'll have a significant list of media mentions. Author promotion occurs naturally as you appear and talk to people.