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 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)

At WP Engine, everything in marketing and sales is included in CAC. Salaries, commissions, coupons, direct advert spend (which you're saying you don't yet have), fees, travel and other costs associated with conferences, etc.. My advice is to err on the side of putting too much in CAC, because that helps you honestly understand the costs. Ignoring some costs just because they don't scale with company size or marginal new customers doesn't make sense to me, it simply means that certain components of your CAC you expect to get more efficient over time. Indeed, they had better! So measure it, instead of ignoring it. You also might find that some of those direct-spend channels are not as inefficient as they seem compared to things like SEO efforts. Or the reverse! All good things to explore of course. I'll also note that at $19/mo in the crowded space of CMS offerings you will find that very few channels will be efficient compared to the revenue you're generating. It sounds like you know that, and are dealing with it with "scalable" efforts like content marketing, however again you should be ruthless in understanding how those costs are really translating into orders and whether that's a financially sensible total strategy.

Your support software should cater to your needs, depending on how your business operates. Fiver uses Vanilla forum and Zendesk. Thumbtack uses Zendesk. Not sure about AirBNB, their help center seems to be custom. Depending on how well funded your are, I would recommend starting with a free plan with one of the help desk SaaS products, or even using open source ticketing platform. Then, as your needs grow and you need integration with your marketplace, there's no reason you can't scale and migrate.

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.