While I would need to read the detail on the specific programs, My perspective is - the purchase of an upvote (one-time or subscription) using Steem/SBD, this is effectively the purchase of marketing/advertising.

• Gain/Loss on the sale of Steem/SBD - I.e. value of Steem $1, cost basis $0.4, gain $0.6
• Deemed purchase of marketing expense with the proceeds. - I.e. $1 of expense.

Whether the marketing expense is deductible/will benefit your personal income taxes depends on the net income position, and whether the Steem account is a trade/business for you or just a hobby.

On the flip side, compensation for selling/leasing upvotes or SP would be income.

See Notice 2014-21 and Section 83. I have more detailed general guides on Steem earnings taxation in the e-book in my blog.

See general disclaimer above

Thanks!