In his recent monograph on German novelists of America, Jeffrey L. Sammons describes his strong disinclination to include a discussion of Karl May:

Sammons's ambivalent attitude toward May results in a relatively brief investigation of the author's reception in the United States. He shows that May's work has generally received scant attention there, suggesting that the personal puzzlement of the literary critic regarding May's success in Germany is quite in line with the reaction of his fellow Americans. As Sammons argues convincingly, May fails to portray North America in ways that could generate a significant interest among larger sections of that society. Most Americans simply cannot identify with May's novels, for even though May drew heavily on James Fenimore Cooper and other sources popular in the United States, he used this material in ways that must alienate American readers. A generally anti-American current pervades most of May's novels staged in North America. But, as Sammons argues, even more than the presence of this bias in May's writings, the novels’ lack of appeal can be explained in terms of the author's inability to represent “what makes America significant in the course of human affairs: the great experiment in creating a democracy, in balancing the often conflicting claims of liberty, equality, and justice. . . .” This ignorance of issues central to Americans’ self-image convincingly explains the absence of May from the U.S. popular-culture canon, much more than the stylistic deficiencies on which Sammons elaborates, quite amusingly, with loathing and bewilderment.

However, May's success elsewhere is a fact, in spite of or (however unfortunate it may be to some) even because of the aesthetic dimensions of the texts.