It's not about return on investment, it's about return of investment.

[randomness]

From Business Week:

The U.S. government received record demand for its bonds in 2011, pushing longer-maturity Treasuries to their best performance since 1995 in a sign that President Barack Obama may have little difficulty financing a fourth consecutive year of $1 trillion budget deficits.

The Treasury Department attracted $3.04 in bids for each of the $2.135 trillion in notes and bonds sold, the most since the government began releasing the data in 1992 during the George H. W. Bush administration. The U.S. drew an all-time high bid-to-cover ratio of $9.07 for $30 billion of four-week bills it auctioned on Dec. 20 even though they pay zero percent interest.

This is one of those things that tends to go on until it reverses abruptly. On the other hand, as long as the Europeans continue their Keystone Cops routine, it'll probably continue.

(I don't know why the dateline on this Bloomberg wire story is tomorrow, however.)