Post boosts
The one way to put weight behind a single post, what it does, and every limit that holds it in.
Sapphire Ultra receives four post boosts a month. Spending one multiplies that post's score by 3x for 24 hours.
This is the only aimable thing money buys on Surf. Boosts are not sold separately, so the allowance is the ceiling, and it is published here rather than left to be discovered.
Where it applies
Only in the ranked feeds, meaning For You and trending, which are the only places there is a score to scale. Following, Latest, Lists and Search are ordered by time or relevance and ignore a boost completely.
What it cannot do
- It cannot work on a post older than seven days. Past that, recency decay has already taken the score it would multiply, so the app refuses rather than spending a credit on nothing.
- It cannot rescue a demoted post. A post moderation has limited takes no boost at all, and the app will not let a credit be spent on one.
- It cannot win you extra slots in one feed. The per-author diversity cap is computed on the unboosted score.
- It cannot pass a filter. A mute, a block, your network scope or a not-interested still excludes the post.
Whether anyone can tell
No. A boost is invisible to readers, exactly like the per-tier multiplier and the reach limits are. The author sees their own remaining balance and nothing else does.