[dodedo]

What you are claiming is not true. Here are some sources that refute your claim:

http://en.wikipedia.org/wiki/In_Rainbows#Sales_and_chart_pla...

In October 2008, a report from Warner Chappell revealed that although most people paid nothing for the download, pre-release sales were more profitable than the total money from sales of Hail to the Thief. The report also stated that the discbox sold 100,000 copies.

[amayne]

And yet they haven't repeated this with subsequent releases. Why not? I really don't know. My guess is that they think this was a one-time gimmick and not a repeatable model.

I could be wrong. I hope I'm wrong.