I appreciate Martin's and Steve's endorsements of my suggestion, and Steve
is quite right in seconding my suggestion that any customer reviews we post
on Amazon give praise only where it is due. Also, Arianne is correct in
sensing a connection between the authors I listed and the Forum. I used part
of the Forum list of book reviews to search Amazon for unreviewed Mark Twain
books. And, believe me, there are a lot more than I listed.

I regard customer reviews as a far from trivial matter. Sure, giving fellow
scholars five-star reviews on Amazon is a nice way to stroke their egos, but
that's not what makes such reviews important. Amazon is one of our windows
to the world. The reviews written for the Forum itself are wonderful for
drawing serious attention to books and keeping us up to date on what's being
written, but the Forum is a mighty small pond. Those reviews get read by
perhaps 400 people at the most. They're written for the already converted.
If we want to keep Mark Twain's name alive and draw more people into our
field, we need to extend our reach. Incidentally, if you look around, you
may notice that we're aging, and there aren't a lot of young scholars moving
into the field. What does it say to people outside the field--especially
young people--that so many books on Mark Twain don't seem be worth anyone's
attention? If you search Amazon for recent books about Mark Twain, you’ll
find that some do get a lot of customer reviews. Most of those books,
however, are written by journalists and outsiders to our field. Some more
than deserve the praise heaped on them, but the huge imbalance in
distribution of reader reviews  seems to convey one clear message, viz.,
that anything resembling a scholarly work about Mark Twain isn’t worth reading.

Not only should we use sites like Amazon, Barnes & Noble, and GoodReads to
praise our colleagues' work, we should also use those sites to get other
people excited about literature in general and Mark Twain in particular. So,
if you can find some moments to post customer reviews, try to  write things
that make whoever happens to see your comments think, "Hey, this Mark Twain
fellow is more interesting than I realized ... maybe I should read more
about him."

P.S. to Martin: You may be right about my having too much time on my hands.
It's an occupational  hazard of being retired. I'll try to find more
productive uses of my time.