Beginning on September 1, 2015, Google and Amazon will begin pausing and blocking Flash ads/applications from automatically playing across the web that are not essential to the performance of a website. The Flash platform has come under fire recently for security issues, and causing performance issues for users which were two of the main reasons for the change. You will start to notice paused ads on Google Chrome, Firefox, Amazon, and more.

What does this mean for me?
If you use Flash ads for advertising on the web then your ads will not automatically play in Google Chrome, Firefox, Amazon, etc.  Ads will instead show a “play” button giving users the option to watch the ad.

What can I do if I use Flash ads?
It’s highly recommended that you consider converting your Flash ads to HTML5 ads so that browsers will no longer block the ad from playing. One thing to keep in mind regarding HTML5 ads though is that they have a much larger file size than Flash ads. This is something important to keep in mind regarding mobile users reaching their data limits as you’ll want to make sure your ad doesn’t drain large amounts of data for users.

For more information:

Amazon’s updated advertising guidelines explaining they no longer accept Flash ads

Business Insider: Chrome Will Block Flash Ads