Originally posted by: aekiel
It's essentially a function of
1) How popular the lead actors are (either individually or as a couple)
2) How much of the story is still left to be explored- especially if the same folks are brought in again. For example KRPKAB S1 was a huge success, S2 and S3 not so much
3) Is the channel open to a repeat pairing? Generally you never get S2 because nobody repeats a pairing. A rare example of a repeat pairing is Nakul-Disha for BALH 2 (they did PKDH on SP around a decade ago)
From what I've seen Sony are perhaps more open to the idea of a second season (their shows don't garner TRP anyway, and even BALH 2, decent as it is with EK's backing, is doing only 0.6 there). With Star, the chances are practically zero.
If there is plenty of demand, they could probably do a finite S2 on the web (Hotstar), but usually money tends to be an issue here, so it's rare.