For years, performance marketing ran on batches: leads collected, bundled, and delivered on a schedule. That model tolerates delay because a form submission doesn't know it's waiting.
A live caller does. Every second between a call connecting and it reaching a qualified buyer is a second where the caller might hang up, and every hang-up is spend with nothing to show for it.
Real-time routing treats each call as an auction that has to clear in milliseconds, not minutes. Bids are evaluated, filters applied, and a decision made before the caller has finished dialing the next digit — which sounds abstract until you watch answer rates change when routing gets faster.
The tradeoff is architectural complexity: batch systems can retry, queue, and smooth over failures. Real-time systems have to get it right the first time, every time, which is why routing infrastructure ends up being the least visible and most expensive part of a pay-per-call network.