I can understand online check in not being available to everyone but self check in is available to everyone(airline dependant obviously)
Time and time again, I see queues which are in excess of 30minutes for check in, and I walk up to the bag drop of the little ATM sized machine hit the screen a few times and hey presto on my way to the lounge

Just wondering what puts so many people off using it... (although works for me as that means i never queue)