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In the first part of this article, I explained what CityVille is, why visibility of a Facebook game matters much more than social interaction factors, and explained how visibility is generated inside Facebook. Now let’s talk about how CityVille keeps users engaged.
Most social games are considered amusements for the majority of players, so successful social game developers focus on delivering that kind of engagement. They are obsessed with retention, a commonly-used term to describe whether players return to a game or bounce from it, and the period of weeks or months that the average retained customer spends in the game before boredom finally sets in. Understanding retention is essential to achieving sustainable growth and revenue in a social game like CityVille.
But what are the levers of retention?
DAU over MAU
In order to understand what's really going on with a game, you need to look at the daily active users (DAU) as well as the monthly active users (MAU). Tracking services like Appdata provide useful summaries of these statistics, as well as a calculation of one over the other. I find that the resulting percentage of DAU/MAU is the best underlying number to really know what's going on with a game.
Whether big or small, the DAU/MAU percentage tells me whether users are playing a social game as a distraction or an amusement (or even a connection, though that's pretty rare), and so gives me an inkling as to the application's true long term potential.
The current percentage for CityVille is extremely high. That's not unusual in the first week of a game's launch however, because everything is new, users are only discovering it for the first time, and the MAU figure has not had a full month to build up. A more stable example is FarmVille:
FarmVille has long been a standard-bearer for engagement on big games. These days it hovers around the 30% mark, which is fantastic, whereas many successful games exist around 20%, and some others drift down toward the 10-12%. Social applications that share quizzes and the like commonly only achieve 3-5%.
Zynga maintains one of the highest overall rates among the big developers at approximately 23%. Crowdstar has only 11%. Playfish/EA has 18%. Six Waves has 8% for its own games and 18% for games it publishes. Disney Playdom has 11%. Digital Chocolate has 16%. RockYou has 8%. Wooga has 18%.
You get the picture. Why this is so has three reasons:
1. Quizzes: The reason why Crowdstar in particular has a low percentage is because one of their most popular apps is a quiz engine. The quiz marketing tactic is a perfectly valid one, and it tends to award high MAU numbers, but low DAU. This often gives a skewed impression of how important a company might actually be in the social game space. Zynga has no quiz engine (that I’m aware of).
2. Visibility Strategy: This is a bit of a repeat from the first part of the article, but the prevalence of publishing options in particular creates more hooks for lapsed players to return to a game. The Facebook economy works geometrically and exponentially, and that applies to retention as well as initial interest.
3. Game Activity: How Zynga structures its games, particularly with respect to time- and click-based dynamics, encourages players to remember to come back and play some more. That's what I'm going to talk about mostly in this article.
Late last year, Playfish released two games that they probably shouldn't have. One was Poker Rivals and the other was Gangster City. Each was, in its own way, a better execution of the incumbents in their genre, Zynga's Texas Hold'Em and Mafia Wars, and yet each has proved to be a failure.
The lesson is not that you can't fight Zynga.
Crowdstar faced off a challenge from Zynga trying to eat its Happy Aquarium market with FishVille, and while both are well past their heyday, FishVille proved to be the loser. Similarly, PetVille tried to take on Playfish's Pet Society, but now has no more than 60% of Pet Society's users.
The lesson is that context matters.
A hidden, but determining, factor for retention is whether this is the first time that players have encountered that game type. As most Facebook games fall into the category of amusements on the Engagement Hierarchy, players don’t distinguish them. It's therefore important to be the first one of that type that the average user sees.
Interestingly, this may have significant consequences for CityVille. After all, social city-building games have now been around for a while, and although CityVille is doing some things differently, the game may end up falling into the same trap as FishVille or Gangster City. It's far too early to tell.
So let’s get on to talking about the game activity.
The core game dynamic of CityVille is click-to-do. Click to build, click to collect, click to plant, click to harvest, click to deliver supplies. It’s reminiscent of the PC game Black and White in that although you are ostensibly the manager of the city, you actually do a lot of manual labour.
So much clicking is oddly compelling. The player doesn’t actually have to click to do everything (collected items will self-collect if left on the ground for example) but there’s a nice feeling that comes from such activity. It’s interactive, and that in turn makes the game mildly immersive by making the player feel like they are doing something, even if that something is essentially just sweeping up.
Click activity on this scale also has a downside, which is that it doesn’t scale well. My current city in CityVille is only a couple of streets in size, but when I do expand it out significantly, I think I might find the extent of such manual maintenance becomes boring.
Timers prevent endless clicking. As I described in the previous post, social games like CityVille employ two kinds of timer: Specific timers on buildings or crops, and general timers in the form of energy.
Timers are deliberately staggered. Planting strawberries takes 5 minutes for them to grow, a cottage generates coins once per hour, and corn takes 24 hours to grow. So you can see why these activities encourage repeated visits. With FarmVille (which uses the same system) there are many apocryphal stories of players getting up in the middle of the night to harvest their virtual beetroot. In fact this sort of timed game dynamic goes at least as far back as the Excel-in-space game Planetarion.
Energy works another way. It is a limit on the amount of click actions that you can take in a short space of time. Some clicks, but not all, dock the player a point of energy. Collection docks energy, for example, but supplying doesn’t. Constructing a building docks energy, but clearing dead crops is free. Energy is resupplied on its own timer at a rate of one point every five minutes, or replenished if the player attains a level.
Timers used in this dual fashion are incredibly effective. What they do is to deliberately set up a conflict whereby players have to wait to do everything they want, but in the mean time can do some of the things that they want. Rather than use one global timer, as Planetarion did, the use of multiple timers creates the sensation that there is always something to do while waiting.
The mix of the two is highly compelling. While players enjoy the click activity (see above), timers essentially introduce delayed gratification, and then CityVille offers premium ways to circumvent some (but not all) of that delay. One of the foundations of monetisation in CityVille is buying more energy, for example. This gets you more activity and more clicks.
(I'll talk more about money in the last part of this article).
The sheer number of rewards in CityVille is intriguing. There are two kinds of reward in the game, let’s call them pellets and unlocks. Pellets are basically any object that appears on the ground when you collect from a building or harvest from your crops.
- XP stars: Experience points, which go toward increasing your level.
- Coins: The more disposable of the game’s two currencies
- Energy Bolts: A free energy point. These drop about once every five to ten clicks
- Reputation Hearts: When you help friends, you receive reputation hearts
- Goods: When you harvest crops.
- Sets: Sometimes a cake or a jewel or some other trinket appears. These items belong to sets, and if you gather complete sets then you gain special awards
The trick with pellets seems to be that the fundamentals required for the game economy to function (coins, experience and goods in CityVille) need to be constantly available. The game might occasionally reward an extra drop of one of these pellets as a part of a regular click action, but the player expects a baseline for their hard work. Otherwise the game feels unfair.
The other kinds of pellet thus become delights. A delight is a reward of happy circumstance and the perception of luck. In a TED talk by Tom Chatfield, he describes seven ways that games reward the brain, and he talks about how the perception of randomness and actual randomness are two different things. Often when players are close to completing a set, for example, they start to feel as though the game is denying them the last piece unfairly. So games (perhaps CityVille is one of them) increase the likelihood that the last couple of items in the set will drop.
Delightful pellets make a game like CityVille feel like more than just a box of functions. They’re trying to add a little layer of thauma into the game by saying ‘This is more than just a dry simulation. Have a cake!’. Delightful pellets make the game seem more charming, and they become compelling in their own right.
Unlocks are a more long-term kind of reward. An unlock opens up new areas of the game permanently for the player, allowing them to do new things that they could never do before, and altering their game experience. Unlocks extend the game dynamic, or in some cases add whole new dynamics, and extension is one the core ways to prevent games (especially amusements) from becoming boring.
CityVille has, broadly speaking, three kinds of unlock: Levels, gates and task trees.
Levels: Levels are a global monitor of how well the player is doing in the game. As the player earns XP from his activities, this goes toward attaining his next level. When he attains his next level, the game replenishes his energy, increases his maximum energy, gives him 1 game cash (the much harder-to-earn game currency), and unlocks new parts of the game. Unlocks might include new kinds of building, new crops or new whole areas that you can access (such as shipping).
Gates: Gates are specific parts of the game that will not permit you to progress unless you complete either a social action or you spend game cash. In the example picture, I have maximised the available population in my town and am required to build some community buildings. One of those community buildings is a police station, and to complete the building I must staff it. Staffing the building requires game cash (which basically means I need to buy some with my credit card) or inviting my friends to staff my station for me. Gating used to be a policy violation in Facebook games because the games used them as compulsory viral mechanisms, but these days games like CityVille use gating as an optional thing to do rather than basing the entire game around it.
Task Trees: Task trees give new goals to the player to complete, but space them out. As I described in the first part of the article, CityVille gives goals to the player in a steady fashion, monitoring a few at a time and requiring that they complete them before moving on to the next. The use of task trees creates quests in the game, such as a quest to set up a bakery or collect 20 cakes, and they ensure a steady supply of medium term rewards. Task trees are a significant part of reinforcing to the player that there is always something to do, or some new delight around the corner. They contribute significantly to making sure that the game does not feel sterile.
Lastly, there is the daily bonus.
The daily bonus is a simple reward for showing up. In early social games, daily bonuses were either flat awards or lucky draws. More recently, they have become chaining mechanisms. CityVille shows not only today’s reward, but if you come back every day it shows you that the potential reward increases. It’s a bit crude, perhaps, but players get the point. Anything that brings them back increases the chance that they will play that day, which in turn opens up all the other possibilities.
The closest analogy that I can think of for how retention works is waiting tables. A waitress is commonly juggling many tasks at once. There are orders to collect, orders to serve, drinks to refill, spills to clean, bills to serve, tips to collect and many other miscellaneous tasks in a live restaurant. All of which combine to create a constant flow of activity and a phenomenon called the open loop.
As humans, much of how our memory and attention works comes from whether we have left something open or closed. We are compelled to try and close what is open, to neatly finish off, collect the bill and receive a tip as a waitress does. Such accomplishment is of innate pleasure to us.
Open loops exist in all our lives. Writing this blog post is an open loop that I must close. Buying Christmas presents is an open loop not yet completed. Checking my inbox closes a habitually open loop. Sending that email I meant to send yesterday closes a loop. Splitting this article into a series creates an open loop in some of my readers’ minds too. Maybe even yours.
Games tap into our need to close loops. Social games like CityVille are expert at doing so because what they create is a never-ending series of open loops. No matter how quickly you play or how much money you spend, there is always something to do, some gate to unlock, some task tree to complete, some daily bonus to claim, some new set to gather, some crop to harvest or some level to attain. It never really ends, and it overlaps various loops over one another such that even if you have run out of cash or coins, there is always something to do – but not for extended sessions.
The loops that the game creates in your mind cannot be closed until you come back later. In the mean time, have a cake!
(That concludes the second part of CityVille Explained. Click here to read the next part.)