Most people know that Google uses a complex system to determine which results to show from a search query. What some people may not know is that this algorithm gets updated periodically.

In mid-April, Google implemented a major change, one that was focused on the mobile-readiness of websites.

While this may seem to be a small technicality, in fact it can have huge impact on anyone that depends on customers finding them through Google.

Here are the key points of the change that went into effect on April 21st, 2015.

This change is different from many Google algorithm updates, in that it is actively encouraging good business strategy. Google’s changes often are implemented primarily to limit – or some would say punish – certain web practices that Google wants to discourage. For example, one such discouraged practice was hiding text on a page by making it the same color as the background.

However in this case, Google is actually encouraging companies to think about their mobile strategy, and to put the resources into making their website “mobile friendly”.

As a large and growing proportion of web traffic, especially web commerce traffic, is coming from mobile devices, this is actually a very good thing for most companies.

As Matthew Tulett, one of the organizers of UnGagged London, said, “I would urge businesses large and small to use the mobile friendly update to take stock and asses their mobile strategy… rather than a headache, this particular algorithm change should be seen as helping businesses focus on ways to achieve growth in areas that, until now, might otherwise have been ignored.”