Stop me if you've heard this before: "Your website needs to be mobile-friendly." Companies have heard this mantra for years, but now a tangible penalty is in effect, punishing websites that don't render well on smartphones and tablets. It's being called "Mobilegeddon."

As of April 21, if your website isn't mobile-friendly, then you will likely be missing out on a lot of traffic. Why? Google shook up the way their search algorithm ranks websites, placing the ones that are mobile-friendly higher in the search from a smartphone or tablet than those sites that aren't.

"As more people use mobile devices to access the Internet, our algorithms have to adapt to these usage patterns," Google announced.

This isn't something to take lightly, either, because Google notes that they will "have a significant impact in our search results." The company hopes that this change — which was announced back in February will make it "easier to get relevant, high-quality search results that are optimized for their devices."

If mobile search engine optimization hasn't been on your radar for a while, it's time to bring it back to stay in the game with your competitors. So how do you ensure that your website doesn't become a victim of "Mobilegeddon"?

Google has a Mobile Guide, but here are some steps to help you through the process:

1. Test your site to make sure you're mobile friendly. Google your site. If the "mobile-friendly" tag doesn't show underneath your URL, then your site needs to be updated. Google also has a Mobile-Friendly Test to see how well your site operates on a mobile device. They also offer a test for a full rundown on issues that affect its search rankings called PageSpeed Insights.

2. Understand what makes your site mobile-friendly. According to Google, your site is considered mobile-friendly if:

  • The text is easily readable without zooming
  • The content on the screen will be sized accordingly, so that you don't have to scroll horizontally.
  • The site avoids software that isn't normally supported by mobile devices (e.g., Flash).
  • Hyperlinks are spaced far enough apart so that they can be easily clicked by the user

3. The process of creating a mobile-friendly site will vary. To ensure your site is mobile-friendly you can have a couple of different designs:

  • Responsive design — the top choice by Google — uses the same HTML and URL across all mobile devices and creates the appropriate display for the user's device through CSS rather than having two separate URLs for mobile devices and desktops.
  • Dynamic serving changes the HTML of your website without changing the URL. It finds out what type of device the user has and changes the code to show something different.
  • A separate mobile website uses different code for different devices, which means that instead of using one URL, a mobile website is basically a new website built specifically for mobile needs.

According to a study from Google and Nielsen, "94 percent of people with smartphones search for local information on their phones" and "77 percent of mobile searches occur at home or at work, places where desktop computers are likely to be present." This means it's time to start making the change.

Some have said that this is biggest mobile-related algorithm change we've ever seen, so talk to your IT department and/or developers to get on the right path of mobile, but as you transition into becoming mobile-friendly, make sure you continuously test your site it to ensure it works properly with all devices.

It may sound like a lot of work, but this change is key to keeping your site visible to your customers, which will inevitably keep your customers happy.