Reddit Premium grants 📝Redditors an ad-free experience, access to a "Members-Only Lounge" and a monthly allocation of "Reddit Coins." The coins are used to "award extraordinary contributions to Reddit." [1] Aside from showing a little badge, the coins don't amount to anything.
January 23, 2019 — In the midst of the 📝Stoned and Single experiment, I noticed that a prompted post on Reddit, created by the official /u/redditpremium account, had been awarded a 'Silver' coin. An advertisement being awarded for it's "extraordinary contribution" seemed highly suspect. It got me wondering if the 📝Administrators had quietly changed the 📝Reddit Algorithm to boost posts that have been awarded—beyond the normal 📝Karma of upvotes—and that the internal marketing team was exploiting its own loophole. So... I awarded my own ad coins from an old account to test.

References
- Reddit Premium, reddit.com/premium
