Calculate how much your virtual world can afford to spend acquiring a new player
Sunday, July 26, 2009 at 6:34PM
Following on from my last post exploring how virtual worlds make money, how much they can expect to make, and the market size, this is the first in a series of articles that will dig into the numbers that drive both the costs and revenues for causal virtual worlds.
In this post I'll explain how to calculate the lifetime value of a player (LTV). In the following two posts we'll look at the user acquisition model, and then dig into the cost of hosting, moderation, and support.
The LTV is a key metric for profitability: the LTV of all paying customers must be greater than the cost to acquire those customers, plus the cost of servicing all free and paying customers.
The lifetime value is driven by three metrics:
- Conversion of free players to paying players
- Spend per paying player
- Length of active membership
Its important to monitor and optimize these three metrics, as we'll see later, small changes can make big differences.
Average Revenue Per User
We start by taking the conversion from free to paying and the average spend to calculate the Average Revenue Per User (ARPU).
ARPU = % Converted x Ave Spend
Lets plug some numbers into our hypothetical world. We'll assume that 10% of our users will signup for a £4 monthly subscriptions. The ARPU is:
£4 × 10% = £0.40 ARPU
If the world also includes micropayments, perhaps through mobile or credit cards, we can extend the model:
ARPU = (% Subscribing x Subscription) + (% Micropaying x Ave Spend)
If we assume that 15% buy through micropayments, and spend an average of £2 per month, then the ARPU is:
(£4 × 10%) + (£2 × 15%) = £0.70 ARPU
Note. A well performing world can expect an ARPU between $1-$2. Our £0.70 falls within that well performing range. However, it would be unusual to launch and hit that target within a few weeks. Instead, developers should take the time to optimize their world and improve the conversion of free into paying players.
Churn
Churn is a measure for the number of players that leave your world every month and is typically calculated as a percentage of the total active user base. For example, a 33% churn means that on average 1 in 3 players leave the world every month.
We can calculate the lifetime of our average player with the formula:
LT = 1 / % Churn
So, for our 33% churn our player lifetime is:
1 / 33% = 3 Months
Lifetime Value
The ARPU calculation gave us the revenue per user per month and the churn rate allowed us to calculate the average user lifetime. We combine these two numbers to get our lifetime value:
LTV = ARPU x LT
So, in our hypothetical world we have a LTV value:
£0.70 × 3 Months = £2.10
Lets revisit churn, remember that the player lifetime is calculated as 1 / % Churn. This means that if we can half our churn we double our revenues. This becomes an increasingly big lever as we start to approach low churn rates.
For example, with a 20% churn:
LTV = £0.70 x (1 / 20%) = £3.50
If we cut the churn down to 10%:
LTV = £0.70 x (1 / 10%) = £7.00
User Acquisition
At this point it would seem reasonable to assume that to acquire a new customer we can afford to spend up to the LTV less the cost of servicing that player. In other words:
Max Acquisition Cost = Lifetime Value - Servicing Cost
However, this does not take into account any viral effects.
While some of your world traffic will come through your own marketing activity, such as ad networks, and search advertising, another portion will come through your players telling their friends. Its this second portion that gives our viral growth.
When we talk about viral growth we often think of exponential viral growth, the kind of growth that Facebook has seen. To be exponential growth you need each of your players to invite and convert more than 1 new player. That is, for every player who joins, they bring another 2 new players with them.
Because the cost to acquire these viral players is effectively zero it can be tempting to optimize for achieving exponential viral growth. However, achieving long lasting exponential viral growth is difficult, and may not be the best strategy.
With a solid conversion to subscription and micropayments you can afford to spend money on advertising or other marketing activity. In contrast, social networks have to focus on low cost viral growth because their ARPUs are significantly lower
Continuing our hypothetical virtual world, if we have a viral growth where on average 20% of our new players invite 4 people then we have a viral factor = 20% x 4 = 0.8.
This means that on average each player invites 0.8 other players, who invite another 0.8 players, who invite another 0.8 players, and so on. This geometric series can be simplified to:
1 / (1-0.8) = 5 Players
So, for every player that we acquire through our paid marketing activity we get 4 for 'free' through viral effects.
Getting to the bottom line, we can calculate the total value of acquiring one customer as:
Total Value = LTV x (1 / Viral Factor)
For our hypothetical model we see:
£2.10 x 1 / (1-0.8) = £10.50
In other words, we could afford to spend up to £10.50, less servicing costs, to acquire one new player. Although, its unlikely you would need to spend over £10 acquiring one new player!
By paying attention to all the metrics discussed in this post its possible to optimize the funnels so for profitable growth through a function of marketing - be that search, affiliates, ad networks, and so on.
In the next post I'll explore two of the costs for servicing your players, hosting and moderation.
At the end of the series I'll share the excel model that combines all of the topics discussed into one template virtual world business model. Of course, any feedback received from these posts will be included.
If you'd like to review the model and input sooner email me matthew.warneford@dubitlimited.com or send me a message on twitter here.
Lastly, learn more about our virtual world platform that gives creatives the tools for designing a world without needing to program.
Matt
Read the second article in the series: Calculate how the addressable market size affects your virtual world business model

Reader Comments (8)
Great post Matthew - and refreshing to see some original research in the VW space.
How do you think your assumptions (primarily about LTV) would be effected by virtual worlds relying just on micropayments/virtual goods and beyond that, in a model of cross-world interoperability, thinking more about the virtual currency perspectives?
Cheers,
Nic
Thanks Nic. Thats a really good question!
Without extrapolating too far, I think you're highlighting that very few parents subscribe to multiple worlds. Yet, my hypothetical world derives more than 50% of its revenue from subscriptions. So, the question becomes, what happens to the LTV when there are more worlds and more choice? Secondly, how does cross world interoperability effect the LTV, and the bottom line margins.
I think cross world interoperability is a fascinating opportunity. Rather than try to explain my thinking in a single comment, I'll spend a little time one night this week pulling together a spreadsheet and a long form blog post.
Would love to hear your thoughts on the subject too, Nic.
Matt
I think the equation for your geometric series is wrong. It should be 1/(1-0.8) = 5.
Thanks Jeff! Good catch.
For those following the thread, I previously had "1 / 0.8 = 5". I've replaced with Jeffs correction, although the outcome stays the same. I did choose the numbers to give an output of 5, but typo'ed the equation!
Thanks again,
Matt
Hey Matt,
Great article, btw. Would love to exchange emails. Don't have yours, but I'm posting mine. I actually run an analytics company for social apps.
Cheers,
Jeff
It is true that advertising is a portion of self-generated advertising and word-of-mouth or viral advertising which comes after the initial advertising investment. The preliminary advertising and certain viral factors to be properly put into motion before the viral advertising will kick in.
Thanks for the comment migreen8753. I agree about the need for preliminary advertising. Launching the world requires a different strategy - the challenges when launching the world are different to growing the world.
When a player comes to the world they want to play and socialize with other players. At launch the world is likely to be empty. Its probably fair to assume players leave an empty world sooner than they would leave a busy world. Therefore, at launch, we need more players to build up sufficient liquidity.
The launch campaign is usually more aggressive, and less cost effective than the process of growing through user acquisition.
I'll blog about the maths in a future post.
Matt
Matthew - great post. We use a slightly different (and very time consuming) way of getting LTV by modelling ARPUs segmented by month of registration. This takes into account changes in monthly retention. We simply add otegether all the ARPUs to caluclate revenue acorss the whole lifecycle. The amazing thing is that our etsimate was with-in $0.02 of the figure calculated using your much faster method. Gave me more confidence in our estimates.