The Book of Snobs is a collection of essays written by William Makepeace Thackeray for Punch. By naming it as such, Thackeray engages in snobbery, for the pretension of the title does not match the content: the essays cannot really be called a systemic analysis of snobbery, comprising, at best, a series of general pointers about snobs and sketches of key snob characteristics and people. It is rather tongue-in-cheek, of course--the subtitle is all we need to look at to see this.*
The central theme of the text may be that nobody can escape being a snob. How we organize society is largely responsible for this. For Thackeray, this comes in forms like the Court Circular (which commented upon the lives of the rich and royal, etc., etc.), and the affect this had upon both the people who read it (e.g., women who grew up on it, learning vanity and pretension earlier than a man might) and those who it is about (who can remain untainted with pride after seeing such attention bestrewn upon themselves in such a cringing way?). It comes in forms like the enormous economic advantage gained from being a rich or noble person. If one could but amass a fortune, one is guaranteed money for one's children, a place in politics, endless comfort, etc. etc., which privileges and thereby makes great those who are born into or rich enough to enter the peerage. How, says Thackeray, could the ordinary human resist? How could one not see these great folk and immediately venerate them (e.g., by virtue of wanting to be them--for how can you hate that which you want yourself)? Even those most cynical are tainted by the virus--even when ideology is lost the society forces one to use it, even to want it.
This critique is in some ways based upon equality--the fundamental building block of why a snob is nothing more than a humbug is that there is no difference between an aristocrat and a farmer. We are born all of Eve and Adam, as it were, and the pretensions of the nobles, the desire to emulate them, to appear fine and fancy, etc., etc., are all lies told by us at the end of the day; it is nothing but vanity and foolishness, a mask for the reality of things, and a corruption of our sense of duty and appreciation of others. (E.g., the duty toward others is harmed by the vanity of buying plate or hosting a dinner party when your daughter goes hungry often enough, thereby one's duty and one's affection toward others are both perverted.) This sense of equality ruffled many feathers at the time of his writing; it landed squarely on the liberal (or even farther left) side of things, which disturbed conservative readers (considering the popularity of these papers). However, this is not all social.
Alongside this broader critique, we see into the lives of some snobs. We see that the poor snob is often made poorer by their pretension, exceeding their expenses by many times simply to look rich; it is to let the daughter starve whilst hosting a dinner party, and Thackeray sees the injustice and irony in this. We see marriages totally ruined by snobbery, or unable to be formed because of it. Marrying for love is nothing--one must have the money, too. The whole of the book portrays snobs of this way, giving sympathy to rich ones (for they are around the cringing, mean snobs who form their social sphere) and poor alike, whilst also often enough laughing at them or pointing out their foibles succinctly enough.
Thackeray is especially notable in this text for satire and humor. Miss Wirt, the pianist, was a particularly funny gimmick--indeed, my favorite section was the country satire. Too many good build-ups to a final joke (like Snob's deception of the Lordator Mrs. Ponto). These satirical portrayals do two things. 1) they are funny, they make one laugh; 2) the are learning experiences, for these characters--no matter the gulf of time between when Thackeray wrote and today--are ever-present. Love of finery, subjection to the rich, etc., etc., all hold sway in modern society. The concept of "flexing" is exactly this, for example. The obsession with rich celebrities, the standardization of beauty, etc., etc., are all this. It is different--commodity consumption for itself, as a means of creating meaning is newer. But the system of economics which Thackeray lived under--the burgeoning capitalism--and our capitalism are in many ways the same, produce the same ends, and--even if Thackeray desires in this book to go more toward free-market capitalism, both of themselves and as an escape from feudal ideas (like the nobility themselves)--these ends are immediately recognizable.
* "The Snobs of England, by one of themselves"