Public interest in the big questions is the lifeblood of theoretical science---an important part of what is needed to keep the enterprise vital. From this perspective, public readership of QG books is a matter of concern---particularly books that break out of the mold. In order to track the public interest in Smolin's recent book "The Trouble with Physics...and What Comes Next" (abbr. TWP) I have been recording the book's amazon salesrank, checked at the same time each day. In March 2007 the TWP salesrank average was 1968. In order to have something to compare it with, I use the average salesrank of the five most popular string books on any given day. The March average was 5785. So one can say that judging by their Amazon salesrank, TWP was about 2.9 times more popular than the benchmark: the average string book in the top five. What do you predict this "public interest ratio" will be for April? Side comment: on a daily basis the indices respond somewhat to events in the media, such as the recent Krauss-Greene debate in Washington, and past interviews with Lee Smolin, Lisa Randall, Brian Greene on national shows, possibly also to book reviews in the press. But the indices may also be showing longterm trends. After books have reached peak in the arc of sales it is very difficult to judge if, and on what timetable, their popularity will tail off. Some turn out to be durable classics and others not.