On Topic...Movie Actors ...they sign a contract to do that till thier Movie Release...
However Television Actors are not bound to any Contract to promote thier Show...They sign a contact for the starting month of the serial for its Promotion...not sure abt the month...But as far as I remember ...its 2- 3 months...if Show is not getting a well deserved TRP...Makers extend the contract...
With YHM...Karan did his Best to promote teh show till the contract period ...post that he does bt yes very rarely...
bt as far as professional part is concerned is did that...rest if anyone has to do ...they can...no one is compelled...
One cant force anyone to do it...
Rest...People really need to find something better in Life...