This letter introduces service ratio-based optimization in multichannel data broadcast systems. The classic pursuit of data broadcast scheduling has revolved around QoS metrics, such as the minimization of the mean serving time or jitter. Recent studies in single channel systems have shown that this approach reduces the client service ratio, essentially forcing clients to abandon the system. Content discarding in single channel systems was then proven to maximize the service ratio. The present work introduces a novel algorithm for service-ratio-oriented assignment of data to multiple channels with different bandwidths. Comparison to related approaches demonstrates the superior scalability of the proposed algorithm.