on Jane Friedman site:

Authors often tell me their first goal in marketing their book is to go after early endorsements. It’s a worthy goal, because getting high-profile people to blurb or endorse your book can add a lot of value to your book’s marketing.

Securing them, however, can be tricky. In the age of social media and email where we potentially have access to everyone, it’s easy to get carried away in your attempts to target a high-profile influencer. I’ve spoken to some authors who create a hit list of high-profile people, or influencers they want endorsements from, and they will just start hitting them up in every way imaginable. Sometimes it works, but more often than not it doesn’t. If you pitch the wrong person in the wrong way, you’ll just waste valuable book marketing time.

Though it can be challenging to secure book endorsements, especially if you’re self-publishing, it’s definitely possible if you go about it with thoughtfulness and patience. And the higher you go up the celebrity food chain, the more involved the process becomes.

Before we go any further, let’s break down the type of endorsement you might want.