Pre-move in Live Chess

As we all know most online chess servers including chess.com allow for you to make a pre move. However, chess.com is the only one that actually takes away time on your clock for a premove (.1 sec)! In my most recent game (http://www.chess.com/livechess/game?id=575185309) I had only .1 sec left and I premoved my last 2 moves which would lead to a checkmate. However, I ended up timing out instead because of the .1 sec taken away for a premove! I suggest to chess.com that they change the premoves in live chess so that they do not take up any time at all (0.0 sec).This would not only help in a situation like mine, but it would benefit anybody who would ever get into a time scramble.

Sincerely, 

screech43

what is pre-move