Statement from Vera Valentine: I do not give permission for any of my works or derivatives (characters, quotes, themes, etc.) thereof to be used for profit (e.g. selling of merchandise such as "mini book" keychains or apparel, creation of "fan art" for subscription-based services like Patreon, use of read-aloud performance for "lives" on social and streaming services, etc.) without an express, clear agreement between myself and the performer/creator/artist, arranged beforehand. This includes my cover art. 

TLDR:  If it's not yours, don't use it. 

Note: This doesn't include using a picture of a cover or short quotes for reading roundups, reviews, memes, etc. That's expected in our social media-driven industry, and totally fine as long as it's not being used to promote something problematic. Thank you for respecting my intellectual property and the work of my designers!