I was under the impression that you shared the SBD with the authors, and knowing that you do not changes my perception of what you're doing, to be honest. That's neither good or bad, because what I think about what you're doing doesn't matter.

Keep in mind that if you shared the SBD you'd still be getting Steem Power for yourself, as well as name recognition and increased reputation. If you think that your time putting the post together is worth 100% of the rewards, then that's fine I guess.

It remains to be seen that your efforts consistently bring exposure to the authors featured. If that is the case, then that's great!

This is how it works with the Steemit Photo Challenge. The majority of the SBD, plus donations, are converted to Steem and given away as prizes, upwards of 300 Steem every single week. The rewarded (7 people, usually) do what they want with their prizes, cash out or power up. Much of the time @berniesanders goes and upvotes winning submissions and comments as well to spread the love. I get to keep the Steem Power and I keep a bit of the Steem generated from the rewards for my time. That is the way I choose to do it, give away most of it.

You should be rewarded for highlighting actual hidden gems, but it should also bring direct value and exposure to those featured. There's a happy balance somewhere in there, I think.