Whenever I consider investing in a B2C startup, I immediately ask about the company's LTV/CAC ratio. From the Corporate Finance Institute:

”LTV stands for "lifetime value" per customer and CAC stands for "customer acquisition cost." The LTV/CAC ratio compares the value of a customer over their lifetime, compared to the cost of acquiring them. This metric compares the value of a new customer over its lifetime relative to the cost of acquiring that customer. If the LTV/CAC ratio is less than 1.0 the company is destroying value, and if the ratio is greater than 1.0, it may be creating value, but more analysis is required. Generally speaking, a ratio greater than 3.0 is considered "good."

I’m less interested in the actual numbers than I’m interested in how the company is thinking about improving the numbers over time.

You could argue that a startup shouldn't be overly concerned with this metric in the early stages because they're still building the initial product or trying to find product/market fit and get the company off the ground. I disagree. B2B startups can get away with deprioritizing this metric in the early days because a good sales team can reliably acquire large amounts of users and revenue in large batches. And because of the way decisions are made within an enterprise, churn is typically significantly lower.

For B2C companies, LTV/CAC should be a part of the story from the beginning. Acquiring individual users is difficult and expensive. And since Facebook and Google, there haven't been that many widespread and effective ways of acquiring new users. Most of the high-quality channels are saturated.

Ideally, B2C startups can bake user acquisition into their fundamental product offering; e.g. a supplier in a marketplace might bring their customers to the platform at no cost to the platform. AirBnB is a good example where landlords will often ask renters to book rentals through AirBnB.

Obviously, this won't be possible for every company. But the point remains: user acquisition and churn mitigation are critical considerations for any B2C startup right from the start.