Heads up webmasters -- please consider updating your javascript snippets.
Originally shared by Ilya Grigorik
All Google+ widgets have been updated to use the script[async + defer] pattern! E.g. +1 button docs:
What's the benefit? Loading widgets via script[async+defer] does not block the document parser (see [1]), and allows the preload scanner to discover the script resource and initiate an earlier fetch (see [2]). Net outcome, both your page and the widget load faster! Have a G+ widget on your page? Check out the docs for guidance on how to update your snippets.
Kudos to the G+ team for taking the lead on this! Hope to see more widget providers adopt the same pattern.
What drawbacks might this have?
Craig W, Sep 30 2014 on 1500wordmtu.com