Traffic & geos
Tier 4 (sub-tier markets)
Operator slang for the cheapest, lowest-monetization geos.
'Tier 4' is operator slang (not a formal IAB classification) for the lowest-monetization markets — sub-Saharan Africa, Bangladesh, Pakistan, Cambodia, Laos, parts of Central Asia. CPCs can be $0.001–$0.005 on pop traffic. Useful for testing creatives cheaply but rarely a profit center on its own. Some sweepstakes and SOI dating offers do clear here at scale.
Example
Operator launches every new pop creative in 'Tier 4' (Bangladesh + Pakistan + Indonesia) for $20 each first to find winners before scaling to tier-1.