In today’s digital age, being connected is as apparent as breathing (‘I’m connected, therefore I am’). I’ve once read that if you have over 500 LinkedIn connections, you are practically 3 steps away from approaching anyone in your industry, in the entire world!

Popular apps like Candy Crush or Dropbox have realized that a long time ago and have built their apps to become super viral.  Their epic success is considered to be greatly related to the viral loops they have managed to build. Through viral loops, existing users are becoming the product ambassadors and bringing new users in, organically (with no premium media costs).

Impressive mobile app virality K-factor value helps top apps differentiate, and sky rocket. Your K factor is your virality indicator.

What is a K-Factor?

What is a mobile app's K-Factor?

The viral K-factor, also known as the viral coefficient, is the most popularly used app virality parameter. It measures how many additional users each user brings along during their entire lifetime (ULT).

To make it simple, let’s assume that on average, each of your app users attracts four additional users, so your K-factor is 4 (that’s a dream K factor, to be clear). App developers are going out of their way trying to optimize their K factor, as it is one of the most important keys to scaling success. An endless stream of organic installs and active users means that you’ve cracked it and you are on your way to living your dream of being a viral superstar.

How Can You Build a Viral Loop?

How Can You Build a Viral Loop?

There are various ways to create a successful viral loops, and I will name a few shortly, but the logic in all of them is the same –  Making your app ‘sharable’ is just the beginning; Making it worthwhile for your users to share it, making it worth for their connections to join and share it onwards – that’s the real trick.

Let’s just put it like this: in order to create viral loops, both your users (your ambassadors) and their connections must benefit from taking an action. It’s your job to ensure it.

Though the logic is the same for every viral app, there’s no one recipe we can share. The best you can do is learn from the pros: analyze apps that have successfully done it before.

Some app developers offer a mutual incentive for their users and their connections, while others build their apps to offer a superior user experience, one that draws in not only existing users, but their connections as well.

You should know, there are many viral loops example. I can only assume that all (or almost all) top apps have built impressive viral loops that have led them to their magnificent viral K factor.

Scaling up is never an easy task. I can’t say it’s impossible without optimizing your K factor, but I would say that focusing on paid installs as your main scaling up strategy is a mission close to impossible. Especially with today’s known ROI metrics that most free / freemium apps present.

Therefore, if you want to master viral loop building, you can assume that insightful viral features are hidden in most of the popular apps we all know and respect. You just need to dig in to find the gold.

Below are some use cases that I love sharing when asked about viral loops, and may help you as well.


Making your mobile app's K-Factor Count Example: Ringya

Ringya allows users to upload contact lists (via Excel or other formats) and create closed groups out of their contacts. Active users also gain extra points for each new member that joins through them. The points can then be used to unlock premium features. Moreover, only Ringya users can update their details in the group list (such as phone numbers or addresses), relieving you from the hassle of maintaining updated group info by yourself.

Gett (Get Taxi)

Making your mobile app's K-Factor Count Example: Gett

This popular app for taxi services is famous for its periodical email campaigns that offer users “Taxi money” coupons for every new user they bring in. They create viral loops because they include a special code that users can share with their connections. So both existing users and the newcomers they bring in can enjoy an incentive.


Making your mobile app's K-Factor Count Example: NokNok

This app lets you see what name your connection gave you in their address book. If this is something you want to know, you must make sure that your connections are using this app too (no worries, it’s anonymous). So, anyone who joins has the same reason: they’re curious.

Candy Crush

Making your mobile app's K-Factor Count Example: Candy Crush

It is one of the most popular and viral games available today. It encourages users to engage their friends and share both their successes and their pleas for help (anyone needs a friend to give you that extra life you’re itching for?). Users facing a difficult level, or just simple addiction, bring in new recruits to help themselves continue playing.


Making your mobile app's K-Factor Count Example: Dropbox

This leading cloud storage service provider has created a viral loop by simply offering extra storage space for users that get a connection to install the app as well. In today’s cloud-driven world, where we’re all scraping for more cloud space, the incentive is truly appealing.

SafeDK's X-RayAll these apps use SDKs and plenty of them. Scan them or any other Android app using SafeDK’s X-Ray to reveal the SDKs within!


SDKs that support app viral loops

You can also help yourself to some tools that provide apps with advanced tracking capabilities of social sharing such as Appoptim or Appsocial. Still, most of these tools will not close the loop for you and you will still need to invest in the product’s creativity and the perks you might offer your users in order for it to succeed in becoming viral. There are a few tools that help enhance the loop, such as K-ivite which assists in creating and tracking the K Factor of mobile apps as well as tracking user growth.

To summarize

My former manager in one of the app companies I worked in used to say: if it were that easy, everyone would have done it. Well, he was so right. But don’t worry – it’s not rocket science either.

The key is not to confuse sharing with viral loop (as many developers often do). Allowing users to easily share your app is embraced, of course, and you must put some effort in it. But, when you think about virality, think strategy. Think motivation. Think of the call to action. Don’t think about “how” people would share your app, think about why they should do so. Give them and their friends a good reason to act. Create a progressive UX superiority that’s based on how many contacts each user has in the app, offer an incentive to both sides (the one sharing and the one who has been invited).