1) It created the concept of a new way to write. The mixture of reality and fiction and then this two again (but is this not magical realism?) permits the reader to ellaborate many a book within the book, as then a lot of writers did
2) Onetti is usually "benchmarked" with Faulkner. Yes, they both created their own space (Santa Maria) but there is where the similarities stop. Santa Maria is the first Macondo, the newest, paradoxically, way to be at leisure in its own territory.
3)Onetti's book was not an instant hit, but in certain circles , and thru viral marketing, ABL virtually dissappeared. The same happened later with other books, especially with the first edition of 100 years of Solitude.
Finally, ABL created the first step in the ladder of extraordinary works of art that came out of Latin America in the 50/60s, that, again, was badly depicted as a boom. It was more the creation of a new current, and a new way to say, new, and old things.
This book will allow you to fully understand this period, and it will open and broaden the way you read