But YC is extracting 6% from promising startups for the same reason that 37signals is extracting millions of dollars for a web-based bulletin board: the total package is compelling.
In YC's case, you're getting access to a hands-on software startup fanatic who's words you already hang on, plus the network of VC's his team has built up over the last N years. "
which is why the "Indian Y-Combinator"(http://news.ycombinator.com/item?id=842150) will (eventually) fail as well.(besides the fact that they won't attract smart people with stuff like how they micromanage the 10,000$ they might give you for 10% of your company - Founders can't operate the bank account, and apparently need a board meeting to decide on line item expenses! See http://news.ycombinator.com/item?id=842882 for details).
Cloning the legal/financial structure isn't enough. YC succeeds because it has very high calibre people leading it, not because it has a specific "algorithm" that others can copy.