7% of the total IPO issuance goes to the bankers. This number is consistent across the street. Once upon a time, anti-collusion investigations were threatened because there was no explanation for why every major bank charges exactly 7%

I've often thought that there is no need for collusion if you can exchange minimal information over public, legal channels and know how to work a strategy that assumes a modified prisoners dilemma. You can often see oil prices or airline tickets operating that way. E.g when one airline raises prices, then sees that no-one is following the rise, after which the price comes back down. Or everyone else is ready to raise prices and ticket prices go up.

Yup; if judges presiding over anti-trust suits had read Thomas Schelling's book The Strategy of Conflict, there would be many more broken-up oligopolies than there are now.

They get a chunk of the other 300m.

Actually it looks like more a chunk:

"By underpricing the stock, Morgan and BOFA gave their best institutional clients a gift of at least $175 million"

http://www.businessinsider.com/linked-in-ipo-2011-5-b

A recurring chunk, you mean. =)