Who accepts Book Tokens?

Could you please elaborate on the various entities or organizations that accept Book Tokens as a form of payment? Are these primarily limited to bookstores and online retailers of literature, or do they extend to a wider range of merchants? Are there any specific partnerships or agreements in place that facilitate the acceptance of Book Tokens? Additionally, are there any restrictions or limitations on the types of products or services that can be purchased using Book Tokens? It would be greatly appreciated if you could provide a comprehensive overview of the merchants and scenarios in which Book Tokens are accepted as a valid form of payment.