作者：jeremyliew

许多迅速实现数百万美元月收入的初创企业都有赖于一个重要理念，即付费市场营销的用户获取成本（CAC）必须远低于用户终身价值（LTV）：

CAC<LTV

用户终身价值的换算公式一般是：

LTV=预期年限x ARPU x毛利率

这里的ARPU相当于每个时间段的每用户平均盈利。这个公式适用于涉及重复购买行为的订阅型服务或电子商务项目。虽然非订阅型服务的用户终身价值通常还需考虑更多细节内容，但其使用的相同断代分析技术却与此相当，因而也可以使用这个公式粗略估计用户终身价值。

LTV和CAC都是运营团队需优化和提高的关键指标。

aim_focus_shoot_win(from kaushik.net)

CAC一般是多个不同渠道用户获取成本的平均值，每个渠道都可以通过更精准、更创意的匹配广告，更良好的登陆页面、支付流程、支付选项和更多病毒推广方式获得优化。

要提高LTV则通常可采用延长用户留存时间，交叉推广和促销活动以增加ARPU，并提高毛利润等方式。

CAC和LTV的作用都不容小觑，但如果在资源有限，团队不得不择其一而行的情况下（游戏邦注：对那些刚起步的小型初创企业来说尤其如此），我会选择关注LTV。这主要出于两个原因的考虑：首选，多数优化内容都与LTV直接相关，并且会提高当前和今后所有用户的LTV，而且不受用户获取渠道的影响。但CAC的优化却与特定渠道联系紧密，而且其优化成效基本上与现存用户无涉，仅与获取新用户有关。所以我们应该在优化LTV上多做文章。

其次，由于LTV通常都会高于CAC，LTV的增长对公司的影响远甚于CAC的下降。

游戏邦注：原文发表于2010年6月15日，所涉事件及数据均以此为准。（本文为游戏邦/gamerboom.com编译，如需转载请联系：游戏邦）

How can you improve LTV and CAC? June 15, 2010

by jeremyliew

A lot of the startups that have quickly reached millions in monthly revenue rely on the arbitrage of being able to acquire customers through paid marketing for less than the lifetime value of that customer.

CAC < LTV

As a reminder, lifetime value, or lifetime contribution as it should perhaps more accurately be named, is given by the formula:

LTV = Expected Life x ARPU x Gross Margin

where Arpu = average revenue per user in each time period. This equation can hold whether you are in a subscription business or an ecommerce business with repeat purchase behavior. Although you need to be a bit more nuanced with non subscription businesses, the same cohort analysis techniques still allow you to approximate LTV in this manner. I’ll post more about this later.

Both LTV and CAC are key metrics that the management teams should be focused on improving.

Usually CAC is a blended average of several customer acquisition costs from several different channels. Each of these channels typically can be optimized by better targeting, better copy and creative on the advertising, better landing pages,optimization ofthe flow through to checkout, more and better payment options, and increased viral pass along.

Some of the tools that can be used to improve LTV include retention programs to extend life, cross sell and upsell campaigns to increase ARPU, and improving gross margin.

Both metrics are very important. However, if resource constraints force a choice between focusing on one or the other (it can be hard enough to do one thing at a time at a startup!), I would choose to focus on lifetime value. There are two reasons for this. Firstly, most of the improvements that can be made to LTV will improve LTV for all users, both current and future, and regardless of channel of acquisition. In contrast, many of the improvements that can be made to CAC are channel specific (e.g. copy of a particular ad) and none of them improve the economics of existing customers, only new customers. You get more leverage out of your efforts on LTV.

Secondly, because LTV is typically already higher than CAC, an x% increase in LTV has more impact to the company than an x% reduction in CAC.

I’d love to hear what others think about this choice, and about other ways to improve both CAC and LTV.（soure:lsvp.wordpress）