Content Propagation

Content on Mehr doesn't spread uniformly — it follows economic gravity. Local content is cheap and fast. Global content costs more but reaches more people. Popular content funds its own propagation. Unpopular content stays local or expires. No algorithm decides what lives and what dies — economics does.

Geographic Propagation

Geographic content follows a bottom-up, demand-driven model. Content starts local and bubbles upward as demand increases.

Cost by Scope Level

Scope Level	Relay Cost	Cache Density	Typical Latency
Neighborhood	~free (trusted peers)	Very high	Seconds
City	Low (short paths, many caches)	High	Seconds to minutes
Region	Moderate	Moderate	Minutes
Country	Higher	Sparse	Minutes to hours
Continent/Global	Highest	Very sparse	Hours (LoRa) to minutes (internet gateway)

The cost gradient is natural — it costs more relay hops to reach distant nodes, so the price is higher. There is no artificial pricing; relay fees accumulate per hop.

Upward Propagation

Content climbs the scope hierarchy through three mechanisms:

1. Demand-driven caching: When readers at a broader scope request content, intermediate nodes cache it. A Portland post requested by 10 Oregon readers gets cached at relay nodes between Portland and the rest of Oregon. Those caches then serve future Oregon requests cheaply.

Portland post → requested by Eugene reader
  → relay nodes between Portland and Eugene cache the post
  → next Eugene reader gets it from the cache (cheaper, faster)
  → after N requests, the post is effectively "Oregon-scoped"

2. Speculative caching: Storage nodes observe demand signals (retrieval frequency) and speculatively cache popular content. A storage node in Seattle might cache a popular Portland post because serving it to Seattle readers is profitable.

Storage node decision:
  observed_demand = retrievals_per_epoch for this content
  hosting_cost = storage_cost_per_epoch
  expected_revenue = observed_demand × average_retrieval_fee × (255 - kickback_rate) / 255

  if expected_revenue > hosting_cost:
    cache the content (profitable to serve)

3. Author-funded promotion: An author can explicitly pay for wider scope by creating storage agreements with providers in broader geographic areas. This is the equivalent of "promoting" a post — paying for reach.

The Self-Funding Loop

When a post earns more in kickback than it costs to store, it becomes self-sustaining:

                    ┌─────────────────────────────────┐
                    │                                 │
   Author pays ────▶ Storage (N epochs) ────▶ Readers pay to access
   initial cost     │                        │
                    │                        ▼
                    │               Kickback to author
                    │                        │
                    │                        ▼
                    │     Reinvest ──▶ Extend storage / wider scope
                    │                        │
                    └────────────────────────┘

   Self-funding threshold:
     kickback_per_epoch > cost_per_epoch → content is immortal
     kickback_per_epoch < cost_per_epoch → author subsidizes or content expires

Popular content climbs automatically:

Phase	Scope	Funding
1. Published	Neighborhood	Author pays
2. Local hit	City	Kickback covers neighborhood; surplus pays for city scope
3. Regional hit	Region	City kickback funds regional storage
4. Viral	Country/Global	Self-funding at all levels; may exceed author's cost

Unpopular content follows the opposite trajectory: kickback doesn't cover costs, author stops paying, storage agreements expire, content is garbage-collected. No moderation needed — economics handles content lifecycle.

Interest Propagation

Interest communities are sparse — they span geography. A Topic("gaming", "pokemon") post from Portland might interest readers in Tokyo, Berlin, and Buenos Aires, with nothing in between.

Interest Relay Nodes

Interest communities naturally develop interest relay nodes — nodes that subscribe to a topic and bridge between geographic clusters:

Portland ──LoRa──▶ [Portland Pokemon fan] ──internet gateway──▶ [Tokyo Pokemon fan] ──LoRa──▶ Tokyo mesh
                   (interest relay)                              (interest relay)

Interest relay nodes earn relay fees for bridging communities. They subscribe to a topic via MHR-Pub Scope subscriptions and forward content to other interested nodes.

Local-First Interest Propagation

Interest content follows the same demand-driven model as geographic content — start local, propagate outward only when validated. An envelope tagged Topic("gaming", "pokemon") does not immediately reach every Pokemon subscriber worldwide. Instead:

Interest propagation stages:

  1. PUBLISH: Envelope propagates to the author's local geographic cluster
     (same as any post — reaches nearby nodes first)

  2. LOCAL VALIDATION: Interest relay nodes in the author's cluster observe:
     - Did anyone in my cluster boost this envelope?
     - Did N distinct nodes fetch the full post? (default N = 3)
     - Did a curator include it in a feed?
     If none of these: envelope stays local.

  3. OUTBOUND: Once locally validated, interest relay nodes forward the
     envelope to peer interest relay nodes in other geographic clusters.

  4. REMOTE CLUSTERS: Each receiving cluster applies the same validation
     before forwarding further. Content spreads through the interest graph
     one cluster at a time, gated by local traction at each hop.

Why this matters: Without local validation, a garbage post tagged with a popular topic would reach every subscriber globally — the envelope is free, so there's no economic brake. Local-first propagation ensures that only content validated by the author's community reaches distant clusters. The author's neighbors are the first quality gate.

Validation thresholds (configurable per interest relay node):

Signal	Default Threshold	Rationale
Boost from trusted node	1 boost	Someone in the local cluster endorsed it
Full post retrievals	3 distinct nodes	Multiple people found it worth paying for
Curator inclusion	1 curator	A human with reputation selected it

An interest relay node can set its own thresholds — a high-traffic relay might require more validation before forwarding, while a small community relay might forward after a single boost. The thresholds are a local policy, not a protocol constant.

Interest vs. Geographic Cost

	Geographic	Interest
Propagation pattern	Dense, local-first	Sparse, local-first then global
Cost driver	Relay distance (hops)	Relay distance (may cross continents)
Caching	Many nearby caches (dense)	Few caches, widely spaced (sparse)
Self-funding	Easy (many local readers)	Harder (fewer readers, higher relay costs)
Typical delivery	Push/Digest (short paths)	Digest/PullHint (long paths, constrained links)
Quality gate	Retrieval demand drives scope promotion	Local validation gates outbound relay

Interest content is generally more expensive to propagate because it crosses more trust boundaries and relay hops. But interest communities can compensate by having dedicated relay infrastructure — nodes that specialize in bridging a specific topic.

Intersection: Geographic + Interest

A post tagged with both geographic and interest scopes propagates through both channels:

Post: "Pokemon tournament in Portland this Saturday"
Scopes: Geo("north-america", "us", "oregon", "portland") + Topic("gaming", "pokemon")

Propagation:
  Geographic: Portland neighborhood → Portland city (high priority, local event)
  Interest: Portland → global Pokemon community (relevant to traveling players)

Readers see it via:
  Portland feed subscribers (geographic)
  Pokemon feed subscribers (interest)
  Portland Pokemon intersection (both)

The economics naturally prioritize the right audience: local Portland readers get it cheaply (geographic proximity), global Pokemon fans get it at higher cost (interest relay), and Portland Pokemon fans get it through whichever channel is cheaper.

Content Lifecycle

Every piece of content on Mehr follows an economic lifecycle:

Phase 1: BIRTH
  Author creates post, pays for initial storage
  Content exists at neighborhood scope

Phase 2: GROWTH (if popular)
  Readers pay to access → kickback accumulates
  Speculative caching expands effective scope
  Storage nodes compete to host (profitable)

Phase 3: PEAK
  Content widely cached, cheaply accessible
  Kickback may exceed storage cost (self-funding)
  Maximum reach for its popularity level

Phase 4: DECLINE
  Readership drops → kickback drops
  Speculative caches evict (no longer profitable)
  Scope contracts back toward origin

Phase 5: EXPIRY (if not self-funding)
  Kickback below storage cost
  Author stops paying → grace period → garbage collection
  Or: remains self-funding indefinitely at reduced scope

Comparison with Other Models

	Centralized (Twitter)	Polycentric	Mehr
What lives	Platform decides	Server operator decides	Economics decides
Content cost	Free to post	Free to post	Author pays
Popular content	Algorithmically boosted	Same treatment as unpopular	Self-funds, propagates wider
Unpopular content	Shadow-banned or deprioritized	Lives until server drops it	Expires when funding stops
Content lifespan	Platform's discretion	Until all servers remove it	Until demand or author funding stops
Spam	ML moderation (arms race)	ML moderation	Economically irrational

Protocol Constants

Constant	Value	Description
Kickback rate range	0–255	Author's share of retrieval fees (rate/255)
Default kickback rate	128 (~50%)	Balanced split for social posts
Speculative cache threshold	Configurable	Retrievals/epoch before speculative caching triggers
Scope promotion threshold	Configurable	Kickback surplus that triggers scope expansion

Geographic Propagation​

Cost by Scope Level​

Upward Propagation​

The Self-Funding Loop​

Interest Propagation​

Interest Relay Nodes​

Local-First Interest Propagation​

Interest vs. Geographic Cost​

Intersection: Geographic + Interest​

Content Lifecycle​

Comparison with Other Models​

Protocol Constants​