An update later today or tomorrow will introduce a bonus to incentivise taking new people into the instances.
When killing an instance boss everyone in group will receive a bonus for every group member that has not killed this particular boss 10 times (account wide), the bonus starts at 20% and is reduced by 2% per kill.
Examples:
A new instance is introduced, nobody has done it: everyone in group gets 160% bonus (260% total) for each kill.
An experienced group (10+ kills) takes a completely new player with them, everyone receives 20% bonus (120% total).
An experienced player(10+ kills) joins a completely new group to help them, everyone receives 140% bonus (240% total).
When killing an instance boss everyone in group will receive a bonus for every group member that has not killed this particular boss 10 times (account wide), the bonus starts at 20% and is reduced by 2% per kill.
Examples:
A new instance is introduced, nobody has done it: everyone in group gets 160% bonus (260% total) for each kill.
An experienced group (10+ kills) takes a completely new player with them, everyone receives 20% bonus (120% total).
An experienced player(10+ kills) joins a completely new group to help them, everyone receives 140% bonus (240% total).