In the past it hasn’t been clear what factors Google considers in their algorithm for mobile rankings. All we know is a “mobile-friendly” tag that is associated with various websites in the mobile search results. Since it was never that big of a thing many website owners have avoided making their websites mobile friendly and it hasn’t really had any major negative effects….but soon that will change because on April 21st 'Mobilegeddon' is going to hit.
Why is this update important? No one is entirely clear what the update will include or change, but it is known that it will change the way Google evaluates how mobile-friendly a website is. Unfortunately It is not known how these factors will change search visibility.
So if you’ve been getting notices about being mobile-friendly from Google, you have until April 21ist until 'Mobilegeddon' hits
Read more: http://www.entrepreneur.com/article/244175