Box Office Collections

[Avadi to America]

Dasa made around 97 lakhs in the opening weekend.. Sivaji also around same figure i think .. so Rajini/Kamal hit movie grosses around 9% of its total in the opening weekend ..

Assuming Mankatha reaches 10c, it would mean that a Ajith hit movie grosses 30% or so in its opening weekend .. !!

it means two things ..
1. awesome opening - great youth base
2. follow up lacks the same momentum - weaker family audience base

Rightly said,especially the second point.
Techinically speaking, the revenue graph with time (week) for younger heros would be more of "S" curve with much steeper slope than rajini/kamal which means the faster/increasing rate of reduction.