Most of the people who are influential for selling books are bloggers. Some of them do have virtual assistants but no physical ones that are at the location to which books get send.

If you have someone like Oprah I don't think that they will sell the books on ebay either.

Don't underrate the complexity of the accounting. I book that's thrown into the trash isn't earned for accounting purposes. If you however get free books that you sell, that's probably income for the IRS.