K Factor系数用于衡量产品的病毒传播率。K Factor=（感染率）X（转化率）。感染率是形容某个用户向其他用户传播游戏的程度（游戏邦注：如通过数据更新或者邮件邀请）。转化率同营销人士熟悉的概念大同小异，是指将感染用户转化成新注册用户的比例。
更简单地说，1 K Factor表示平均1个用户带来1个新用户。K Factor越高，社交游戏发行商越受益，因为这是个获取新用户的有效工具。
The Secret Glossary of Social Games Analytics
If you’ve been reading up on social gaming, you’re probably familiar with terms like “microtransaction,” “core gamer,” “casual gamer” and “viral.” Maybe even “Freemium.” But buried in all the talk of Farms and Fish is a new lexicon that combines old school statistics with the latest in search engine analytics.
So, for those of you who are neither stat geeks nor analytics jockeys, here’s a crash course in basic terminology for social games metrics.
A term carried over from Telecom companies, Average Revenue Per User (ARPU) is measured as total revenue divided by the number of subscribers. This includes revenue from subscriber fees, virtual goods, affiliate marketing and ad impressions. Because social games are so metrics-heavy, ARPU can be broken down by day, by country, by demographic, or by pretty much any other metric.
The turnover rate (or “attrition rate“) of a social game’s active players. The noise level in casual gaming is extremely high, which means social games have a user base that is constantly changing as gamers abandon the game or delete the Facebook app. Churn refers to this constant loss and gain of members.
A common term in statistics, a cohort is “a group of subjects who have shared a particular experience during a particular time span.” In social gaming metrics, cohorts are used for analyzing retention. By organizing users in groups such as “everyone that visited on June 10th” and analyzing the percentage that revisit, you can pinpoint what promotions are having the greatest effect.
Daily Active Users (DAU) is just what it sounds like: the number of active users over the course of a single day.
The DAU/MAU ratio is one of the hot metrics in social games. Comparing Daily Active Users to Monthly Active Users shows roughly how many days per month your average user engages with your game. If you have 500,000 daily users and 1 million monthly users, the DAU/MAU is .5, translating to the average user logging in ~15 days per month. The DAU/MAU ratio is strongly correlated with social gaming success.
According to Lisa Marino from RockYou, the minimum threshold for DAU/MAU is .2. This is necessary for a game to hit critical mass virality and engagement.
Facebook players typically have dozens of “active” games at a time. Engagement measures how long they spend playing your game. How many features do they access? Are they spending hours or seconds? How many pages does the average user view? What percentage are returning visitors?
An entry event is the first action a user performs when they enter the game. Online social games can track every action you perform, and the Entry Event Distribution is one of the more important metrics to follow. What do your users do first? Which entry events are the most effective at bringing people back?
For example, you might find that a majority of your users log in when they receive a gift, and the first thing they do is check that gift. By determining the more popular entry events, you can push more resources towards them, thus increasing retention, engagement and re-engagement.
The opposite of entry events. Exit events are the last actions a user performs before exiting the game. Tracking the Exit Event Distribution helps show why users are disengaging with the game.
K Factor measures the virality of your product. K Factor = (Infection Rate) * (Conversion Rate). An Infection Rate is how much a given user exposes the game to other players, such as through status updates or email invites. A conversion rate, as marketers know, is when that “infection” results in a new sign up (or “install”.)
Put more simply, a K Factor of 1 means every member is bringing you one additional member. A high K Factor is treasured by social game publishers, because it becomes a very effective vehicle for bringing in new players.
Lifetime Network Value
The value a user provides to your network over the course of their entire “lifetime” on the network. For instance, is the user contributing to viral effects? Evangelizing the game? Contributing positively to ARPU? This is compared to the User Acquisition Cost, or how much it costs (via marketing and viral efforts) to bring in new members.
According to Facebook app analytics provider Kontagent, a (very basic) equation is 1/(1-k) * Monthly ARPU * User Lifetime.
Like DAU, Monthly Active Users (MAU) tracks the total number of users in a given month.
Gamers stop playing eventually. Re-engagement is how you get them back. It includes re-engaging gamers who have been signed off for an hour, a day, a month, or more. There’s a lot of competition out there, so implementing and tracking re-engagement practices is a must.
Think of it as the opposite of churn. Retention is how well you maintain your userbase.
Viral growth is the name of the social media game. Measured by K Factor, the Viral Rate/Virality shows how much your users are promoting, evangelizing and spreading your game. Because of this, social games are increasingly built around cooperation, competition and the constant addition of new features, which increase virality. Every feature is a source for growth, whether it’s “liking,” Facebook notifications or tweets. Not often confused with “virility.”（Source：wavedash）