question on booking next cruise while on current

[momof2tx]

This will be our first DCL, but have been on other cruises. I've seen quite a bit of talk about people booking the next one while on the current one. Do they give a $$ discount if we do this or is there a special benefit to it?

[TiggerzFan]

We just rebooked onboard and for a 7-night booking they offer 10% off and a $200 stateroom credit. Am not sure about incentives for 3 & 4-night sailings.