客户获取成本计算器（CAC）
CAC 指标可帮助你分析广告投放的有效性，并估算获取一位客户的成本。使用它来跟踪营销渠道的效果，并在不流失客户的情况下优化成本。
LTV : CAC
1 : 1 or less
The business is working at a loss, you need to make
changes as soon as possible.
2 : 1
Customers bring two times more money than it costs to
acquire them.
3 : 1
This is the optimal ratio to hit. It means the business
model is profitable.
4 : 1
The business is very lucrative: acquiring customers is
cheap, and they bring great value to the company.