Thinking about SM groups...
I suppose the potential would be...:
- How good they are musically
- How good dances they are
- How good looking/ good visual they have
- How charming they are
- How is their personality or skills they could have so audience would like them
I think maybe this things and others that don’t come to my mind right away.
Of course everything can be trained and get some (little) plastic surgeries during the years and make them shine more, be more skilled in different areas (as they all do and preference in what they like as we already know).
But also with the years and after the “big boom” the fame will fade, so they search for other places to fit apart of the idol image. Acting, radio, MC and other audiovisual stuffs....
Based in all these things, during the idol time, what would be the impact each individual (and also as a group) they have to influence the young masses? Everything, through all the mechanisms the companies and the people of the band have to make more money in different ways.