If we are to imagine propaganda as the one-sided dissemination of information with the intention of influencing public opinion, then The Communist Manifesto is the greatest piece of revolutionary propaganda. Lefties find inspiration in Karl Marx and Friedrich Engels' pages, not because they contain an incredibly detailed explanation of a more progressive society, but rather for the somewhat romantic - and not particularly analytical - condemnation of rampant capitalism. Those who question the merits of our present form of society are angered by the persuasive arguments poetically proposed by Marx and Engels. This, of course, was the intention of our monumentally-bearded writers.
Marx and Engels wrote The Communist Manifesto with the objective of galvanizing the latently rebellious working classes. The text was proliferated not to spark intellectual debate, but rather as a call to arms. Marx and Engels unapologetically indulge the art of proselytizing at the expense of a detailed analysis, and thus only offer somewhat inadequate guidelines for a purportedly better form of society. After reading The Communist Manifesto, one might felicitously find oneself craving an alternative to capitalism, and yet one wouldn't know quite what to expect from such an alternative.
This isn't to suggest that there is no worth in The Communist Manifesto. Over a hundred and fifty years after the publication of their famous work, Marx and Engels' criticisms of untamed capitalism are still important. In order to fully understand their conception of a fairer society, however, one would certainly need to read further on the subject. The Communist Manifesto alone offers surprisingly little insight in terms of actual communism.
For grand theories of communism, or for a far more in-depth analysis of the economic flaws of capitalism, one should probably turn to Marx's Das Kapital. Unlike The Communist Manifesto, Das Kapital contains complicated theories of alienation, commodity fetishism, wage oppression and quite a bit more. It's not, however, the kind of book that one can happily read while drinking a Horlicks and snuggling up for the night. Das Kapital offers little in terms of inspiration, especially for us normal folk. It's all very mathematical and economical, and it doesn't have brilliant little lines like 'all that is solid melts into air' and, of course, 'workers of all lands unite'.
There isn't a single piece of great propaganda that can only be understood by the supremely intellectual or the relentlessly patient. That's not how propaganda works. Propaganda, by its very nature, must have popular appeal. Marx and Engels were aware of that.
The Communist Manifesto, of course, was and indeed still is vastly popular. It is a great piece of revolutionary propaganda precisely because it is simplistic, poetic, persuasive and accessible. It doesn't baffle its reader with complicated theory, but entices him with grandiose dialect and powerful rhetoric. Having recently re-read what is somehow believed to be one of the defining texts of communism - despite containing very little about actual communism - I learnt two things: first, capitalism seems to be quite unfair; second, Marx and Engels sure know how to write. All things considered, however, I think readers would need to know a little bit more about communism before they attempt to overthrow the entire system.
Nonetheless, if you haven't read The Communist Manifesto and you're feeling a little bit rebellious, get yourself a Horlicks, snuggle up in your factory-manufactured duvet and enjoy this masterclass in revolutionary propaganda.