How Buyers Are Selected for a Call

The Router Picks the First Eligible Buyer

When an offer needs to hand a call to a buyer, the system
iterates eligible buyers in priority order and returns the
first one that can take the call. Eligibility means the
buyer is in the offer's buyer set (directly or through a
buyer group), is within business hours, is not paused, is
not maxed out on caps or concurrency, and satisfies any
per-call predicates (token matching, filters).

Priority: Tier Ascending, Weight Descending

Priority is determined by tier (ascending) and weight
(descending). Tier 1 buyers are considered before tier 2.
Within a tier, higher weight wins more often through a
weighted-random distribution, not deterministic ordering:
a weight-3 buyer receives roughly three calls for every
one call a weight-1 buyer receives in the same tier.

Buyer Group Overrides

When a buyer belongs to a buyer group, the group's tier
and weight override the buyer's own. This lets operators
tune priority at the group level without editing each
buyer.

Route-By Type

Each buyer has a route-by type setting that controls how
its priority is calculated:

• Tier (default): the buyer is sorted by its configured tier and weight.
• Revenue: the buyer's effective priority is derived from its historical revenue.
• EPC (Earnings Per Call): the buyer's effective priority is derived from its earnings per call.

Because route-by type is per-buyer, different buyers under
the same offer can each sort by a different algorithm.

Concurrency

Every buyer has a concurrency cap: the maximum number of
simultaneously live calls. If the buyer is at capacity the
router skips to the next buyer. A default call router
fires when every eligible buyer is at capacity.