How Buyers Are Selected for a Call

The Call flow 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.
• Bid Price: the buyer's effective revenue at the time of the call
• 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 call flow skips to the next buyer. A default call flow fires when every eligible buyer is at capacity.