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It would be great to be able to pay by upvoting the publication somehow.

The flunctuations in the price of steem will be a major hindrance to the upvote payment. After the 7 day period has lapsed, there's every possibility that the value of the vote might be less than the worth of the book, that's a loss to the writer. It could end up being more than the worth also. I feel the best way to handle payments will be through transfer of funds (SBD/steem)

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