Does your webpage use Flash?  If so, Google will now show a warning to all mobile users, warning them that the site “may not work on your device” with the option to “try anyway”.

Even more significant is the fact this warning will replace the entire description for the search result, meaning if your site is impacted by this, you can’t even entice the user to click on your result anyway because the description shows exactly what the searcher was looking for.

If you have a website that uses Flash, and if you don’t have a mobile-friendly version of the site, you will definitely see a drop off in search referral traffic due to this change.

Why did Google make the change?  Again, Google is about providing the highest quality search results, and being on a mobile device and ending up on a website your phone can’t handle is never a good user experience.

This follows closely on the change they made last month, where users who were on a mobile device and Google served a result where the user would end up going to the homepage instead of the internal page the search results showed, it would also show a warning advising searchers of the issue.

This new change wasn’t unexpected, and is probably the second highest complaint from mobile device users about websites, after the homepage redirects.

With mobile market share growing rapidly – and Matt Cutts at SMX Advance saying he believed we would see more than 50% of searches via mobile devices in the very near future, having a mobile friendly site is crucial.

If you have a site that isn’t mobile friendly and you have had a fair percentage of your traffic coming from mobile and tablets, you should make changes to your website immediately, otherwise you are going to find yourself with rapidly dropping search referrals – especially if you use Flash or redirect to the homepage.