When working on a double-sided marketplace how do you work out cost of customer acquisition?

I think you're looking at this the wrong way. Your customer acquisition cost is not something you should benchmark against other businesses. Without knowing more, like your short and long-term goals, it's impossible to answer. Two companies with similar business models may have different answers to this question. A venture-backed startup trying to keep up with aggressive revenue goals may be able to stomach an astronomical CAC. A bootstrapped startup that is not seeking venture money may aim for slower growth and much lower CAC. I suggest setting up a call with a marketing or finance expert to determine what CAC is appropriate for your company and how to get there.

I always suggest going "uncomfortably narrow" initially so that you can really dial in the user experience and build liquidity first. Going broad will be tougher as there's too much noise to signal. Also, it's best to fake the supply side initially of you can to improve the buyers side first, then figure out supply & quality afterwards if customers are buying and you've proven out a demand strategy that will work.

I like to separate your question into 2 sub-questions: #1 How do we determine which side to charge? #2 How much is the right amount to charge? On #1, my answer is that you can charge the side(s) for whom you add the most value. In your examples, Uber really solves a big problem for drivers, it's that they sit idle for a good part of the day, so are willing to pay a lot for new leads. (their alternative is no work) Consumers are charged more for the convenience of a private car but they are probably not so much willing to pay more for a taxi, even if they can hail one from their phones. For AirBnB, it's a mix, it's a way for landlords to monetize idle capacity which they are willing to pay for, but it's also a way for a renter to pay less than they would normally pay for a hotel. On #2 (how much), I like to triangulate a number of factors: - What's the maximum amount I can charge one side, while still being a good deal for them. - How much do I need to charge so that I can become profitable? (the economics are quite different if you charge 3% vs. 12%) - What are comparable services charging for substitutes/competitive offerings? I will just add that there is no formulaic way to determine pricing strategies (curated vs. open), and it's a lot more about what's the comparable and what the value delivered is. That's how I approached the question while deciding the business model at ProBueno.com (my startup)

To answer this, you need to have a working model for your customer LTV (Life Time Value). Most startups can't accurately estimate their LTV, so if you don't have good enough data, then building your CAC based on assumed LTV numbers can be fatal. In this case, it's better to evaluate your CAC costs based on the months of revenue it takes to recover the cost to acquire the customer, and ultimately this calculation should be net of any costs associated with providing the service on a monthly basis and, even more conservatively allow for a healthy degree of churn. Keep in mind that this calculation doesn't evaluate your true profitability only the capital efficiency of your customer acquisition spend. Hope this helps. Happy to talk this through in more detail and with more specifics to your business.

The best way to solve chicken and egg problems for marketplaces is to prove market need on each side independently first with a low-cost MVP-type test. Once you've proven the market on both sides with metrics it is much easier to leg in supply and demand with a strategic or enough funding to match a market on a local or niche level to ensure liquidity. For a deeper analysis, here is a post on medium that I wrote... http://bit.ly/1k2vYbY Also, feel free to schedule a call with me if you'd like to dig deeper.