A shorter name is easier to remember and less likely to be misspelt. The last thing you want is for people to forget your name or have trouble spelling it. If you are a competitive gamer, you may want to choose a name that reflects your skill level.
When choosing your Steam name, be sure to keep the following tips in mind: Whatever you decide, be sure to pick a name that you will be happy with for the long term. Some gamers choose to use their real name as their Steam name, while others choose to use a gaming alias. How to Change Steam Profile Name (Username)?.