The more coins you have the quicker they will stake (after they reach the 24 hr minimum age).  Your chance to stake is relative to the total coins available to stake.  Each day that your coins do not stake their "stake weight" increases by the original amount.  

For example:  you have 100k coins that are 24 hours old, your "stake weight" is 100k x 1 = 100k.  6 days later they still haven't staked but your stake weight is now 100k x6 = 600k.  Your chance to stake is now 6x higher than it was when your coins first matured.  If your coins had staked on the first day you would have received 100 coins as a reward.  If they stake on the 6th day you will receive 600.  The percentage returned by staking is cumulative to a max of 100 days.  If your 100k coins stake on the 44th day, you will receive 4,400.

Be aware that moving coins around may reset your staking age.  Use the coin control feature to monitor the age on your coins.  http://wiki.hobonickels.info/index.php?title=Coin_Control#Tutorial has a very nice description on how to use the coin control.

In a nutshell, the more coins you own the quicker they will stake upon reaching maturity.

If I made an error, I'm sure someone will point it out