How established your current Chess.com rating in that time control is. The Glicko RD will lower as you play more games, and your rating will fluctuate less from game to game.
If you go a longer period in a given time control without playing any games, the Glicko RD will slowly rise.
Its purpose is to declare an error deviation because a person's rating strength who has not played very much or in a long time is less accurate than someone who plays often.