Lead distribution systems and methods distribute consumer business leads received from lead sources for routing to one or more destinations that use the leads and/or forward the leads to another destination. A quality level is assessed for each lead source, based in part on a percentage of leads from the source that result in a desired business transaction with the ultimate user of the lead. The system identifies a set of most profitable destinations for each lead, while maintaining a desired overall quality level and flow rate of leads routed to each destination. Adjusting the quality ratings of the lead sources may advantageously be used to affect the placement of their leads with destinations.