Solid introductory text for graduate level studies. Highly, highly detailed. Richly provides historical context for the writings of the New Testament, but does so without binding itself to the New Testament - that is, it doesn't start with Matthew and give you bits and pieces of context to help make sense of Matthew. Rather, this book is an introduction to the history and culture of antiquity in the Hellenistic world. If you've ever wondered how the Ptolemaic dynasty managed its economy or contributed to poetry, or what kinds of fruit came from Persia but were popularized in Rome, this is your book.
By refusing to predetermine excessively which details are "relevant" to the New Testament, the text instead opens the mind of the student to consider how to relate the historical context to the early Christian writings, and in this sense of relevant to early Christian studies in general (not just New Testament). Given the (lack of) background in Classics for many students of early Christianity, this can help fill a big gap and serve as a reference text.
All that said, it is dated; by virtue of when it was published it cannot take into account the explosion of scholarship in the last couple decades nor the more recent forms of criticism.