Hello and welcome to the Feedback Loop edition of Slate Money, your weekly guide to the

Business and Finance News of the Week. I'm Felix Salmon of Fusion in New York, and we have had

an astonishing amount of awesome feedback from you guys, mostly in the form of

emails. So we're going to spend a little bit of time going through some of those letters

and responding to them. And after that, we're going to talk about cool kid tech companies and

why they aren't using investment bankers for their mergers and acquisitions,

then we'll move on to Amazon's new local register payment system, they call it.

It's going to be a full show.

But first let me introduce our regular guests.

There's Kathy O'Neill, head of the lead program for data journalism at Columbia University.

Hi, Felix.

Hello, Kathy.

And Slate's own moneybox columnist, Jordan Weissman.

Good to be here today.

I'm so happy that you're happy to be here.

Anyway, first and foremost, the mailbag.

I've been looking forward to this all week because we promised it last week, and now I get to do it.

I have to say first that we got lots of mail about my thought experiment last week, where I talked a bit about a magician doing a card trick, and I'm not going to talk any more about that,

because next week we have a very special guest,

Emmanuel Derman himself from Columbia University,

and we're going to devote an entire segment

to that little card trick thought experiment.

...