Evaluating Growth Channel

You're the Growth Leader for a meal planning app. Your team has scaled a new user acquisition channel in the previous month after seeing low customer acquisition costs.

However, month-2 customer retention from this channel is lower than others. Due to diminishing repeat rates, the leadership team wants to shut it down. The channel team is pointing to its low costs.

→ How would you objectively evaluate this channel's performance?
→ What data points are crucial for making this decision?
→ What non-quantitative factors should be considered?

See hint