I haven't copyrighted the idea, and I wouldn't give a fuck if someone else had, so use the idea if you like.
But, this post actually has " SBD" in the title, so perhaps that's the only reason? Lol. I won't know until my next post, though I would like a way to easily show that the post pays those who engage with it.
Perhaps I will come up with a logo that links back to a post that explains the 20% giveaway. Then you or anyone else could also make use of the logo on posts that you want to give 20% away on. Could become a legit thing on Steemit that people do, like declining payout, only giving back some of the payout.