Firstly, your book needs to have an eye-catching cover with elements reflecting the story and mood you tell in your book including properly placed, sized and carefully selected typography.
Sales & Marketing
Also, you want your cover to look professional. Busy book market requires that. Above all, your cover is one, powerful, sales driving tool. In other words, amateurish cover won’t sell well.
Furthermore, you need your cover to fit your story genre and stand out from other covers so it meets your reader’s expectations and can be easily recognizable from the distance.
No Display Issues
Finally, you want your cover to be properly formatted for online display and print so it looks the best as it possibly can across all devices, platforms and on the bookstore’s shelf.