Google “Candy Crush Invite” and you will discover dozens of memes about this virality feature. Since its launch in 2012, we have all been gophers to Candy Crush invites from some relative or high school friend we haven’t talked to in seven years. Fast forward three years and Candy Crush is still topping charts and using this, among many other, viral features.. We’re diving into three examples of sticky social virality features for mobile apps and how developers can implement them successfully.

Connect to Facebook

Facebook Login is arguably the most important feature to put in a mobile app for user acquisition, retention, and re-engagement. It is also arguably one of the more difficult things to get people to do as they don’t want their privacy invaded or things shared to their wall (we are talking to you, Candy Crush!). Games can incentivize Facebook login through giving away in-game currency and other genres can recommend Facebook login by adding value to this feature like allowing cross-platform functionality.

Once someone has Facebook connected the marketing team should use this to their full advantage. First, you can use the connected users as lookalike audiences in your Facebook user acquisition campaigns – which will target people that have similar characteristics to the default user. These characteristics range from demographic (female, 22 years old, living in California) to things they like (horror movies, dark chocolate, coloring book apps) which is a great strategy if your app monetizes through in-app purchases because you can create a lookalike out of purchasers only.

The marketing team also now has their email address and should send email campaigns to users to retain them – but don’t bombard them either. Things like promotions, game updates, and asking for feedback are great ways to retain your users while utilizing different social features for mobile apps.

But, how do you engage these users to come back if they haven’t used the app in an extended period of time? Run a targeted re-engagement Facebook campaign focused first on spending users and then to the general user base to get them to come back – retaining users is way less expensive than acquiring new ones.

All three of these things can be done by adding the Facebook SDK and Facebook Login Plugins.

App Invitations

Everyone’s simultaneous favorite and least favorite virality feature out there! If it didn’t work, King and thousands of other developers would not still be using it. The best way to get users to invite their friends is two-fold: design a great app that people want to share and incentivize them for doing so. App store and Facebook policies for incentivized invites have changed over the years but the latest trend in mobile games is to incentivize the install – not the invitation. Zynga does this by offering free coins to the sender if their friends download the game – not for sending the invitation.

Other mobile apps have taken this feature off of Facebook and went with a code-based solution that they can email or text. Uber and Lyft both give users personal codes that earn them free rides when their friends take their first ride. Although Lyft and Uber still have to pay the driver the fare, they are getting easy users. (Feel free to use my codes so we can both share in this viral feature!

Whether you can give away free in-app credits, which don’t cost anything, or have to pay to close this viral loop, in the case of Uber or Lyft, this feature is definitely worth developing to incentivize current users of the app and gain traction with new users.

In-App Gifting

Another  social sharing feature is the ability to gift in-app items to other users and is huuugely popular in mobile games. As a previous mobile game community manager, I came across Slotomania’s SuperGroup where I would see players posting that they were in the hospital and wouldn’t be sending in-game gifts out this week. People are passionate about this feature but I have yet to see this feature be popularized by other app categories but am eagerly waiting. Apple has a few rules to this feature so make sure to abide with them before implementing.

Overall, implementing social virality features for mobile apps needs to be beneficial both for you as a developer and to your users. Don’t bombard them with sharing to their wall or asking them over and over if they want to connect to Facebook. Create easy and meaningful ways for them to want to use these features and embrace when they do.