A Facebook user who have +4000 and more or less friends and he wants to add them all to a page/Group/Event of his own or someone's else, finally it's solved, by one line of Code in your browser at the time when you attempt to you add friends, you can just select them all at the same time, watch the video :
Have not time to watch the video so, could you summarize what is all this about? Reading often takes a fraction of the time that watching a video, only exception is when a video explains step by step the how to of something, but if it's only a line of code what you propose, simply write it down here to read and see.
With many browsers (for example Chrome) you can get an extension (for example: Facebook Friend Inviter) - which basically allows you to invite all your friends in one click.