The source – support.google.com
From May 18, 2021, Google will no longer support global digital book ads in Shopping ads. This means that all Listing ads for digital books will be rejected at the offer level, including those that are enabled. The Google Merchant Center Help says the listing includes PDFs, ePub books, MOBI, and 子 書籍 formats.
This update applies to e-books only. There will be no changes for prints and audiobooks. If their ads are rejected for misclassification of digital books, please request a Merchant Center review. Google developers promise to quickly solve a similar problem if it happens.
While the company is not yet ready to ensure that digital book ads meet high standards in Shopping ads, the company believes it is the right solution to protect users, publishers and the Shopping ecosystem.
Book information in other formats, such as print and audiobooks, can be posted as before.