Every 10 minutes online in the game, you receive:
1 'Online Point'.
These points can be used to redeem rewards in the online points store (OP Shop), which is updated periodically.
Points are transferred from your character to your account every 24 hours, so you can use them in the store.
You can track the amount of points for each of your characters through the control panel -> account information. Whenever points are transferred to your account, your hero's online points are reset and start counting again.