User Onboarding is the process of increasing the likelihood that new users become successful when adopting your product.

Back in 2013, Skype reported having 300 million users, which would have made them more populous than the 4th largest country in the world. If they’ve kept growing like they were since, they’re almost definitely now the 2nd. How did they get so many users?

They adopted a strategy based on onboarding their users.

Onboarding is a whole new approach to providing a successful user experience in the first steps of using software. You might say, if its software they have to use (and sometimes it is), then I don’t need to worry about this. Think again. It’s all part of ensuring user satisfaction and putting yourself in their place. A poor onboarding experience makes every part of a product company work harder: marketing teams have to acquire more and more visitors to keep filling a leaky funnel, and sales & support teams have to spend their days hand-holding confused signups instead of scaling things out for the whole user base. That pulls resources away from the product itself, resulting in slower growth, missed opportunities, and competitors passing you by. It’s like breathing through a straw – sure you can do it, but it’s exhausting. And you sure won’t win any races while doing it. Remove the bottleneck, and you go from surviving to flourishing.

From : https://www.useronboard.com/training/