IMPORTANT: Place it just after the opening <head> tag to ensure it processes first and does not get blocked by another script in your page. This will allow the block to work as fast as possible.
Our servers respond in 100 to 300 milliseconds so if the script is the first to process in your page, then the block will be almost instantaneous.
The block script is an asynchronous non blocking script, hence it will process while the rest of your web page loads. This will prevent any increase in page loading time for visitors who don't end up getting blocked.