What core data point determines the success of a mutually beneficial collaboration strategy?

The core data point determining the success of a mutually beneficial collaboration strategy is the measurable increase in relevant traffic and engagement for both collaborating channels. This is assessed by tracking metrics such as new subscribers gained from the collaboration video, watch time generated by viewers from the partner's audience, click-through rates on cards and end screens leading to the other channel, and overall audience overlap and engagement levels. A successful collaboration results in a clear and quantifiable benefit for both partners, demonstrating that the joint effort effectively expanded their reach and connected them with a new segment of engaged viewers who are likely to become consistent audience members.