(I had to edit this review because Amazon's filters now do not allow "profanities" in the review so I had to use `MFing' for the title, etc)
This essay/booklet is a rather interesting little discussion of what McGinn understands by the vulgar term "MFing." Basically, MFing is like a BS or a lie in that it has an element of deception but the last two things do not necessarily have an element of emotional manipulation so characteristic of MFing.
BSing involves making the hearer falsely think the speaker is competent on some topic under discussion when the speaker really is not. The distinction between a BS and a lie is first elaborated on in Harry Frankfurt's famous essay and booklet "On BS." Truth does not even come into the equation for the BSer; it's irrelevant to the him; he doesn't even acknowledge it. His BS may or may not be true but reality is irrelevant to his purpose of BSing. Liars on the other hand purposely seek to get around the truth, thus he necessarily takes it into consideration (so as to avoid it). The liar seeks to not only make the hearer think he knows what he is talking about but seeks to make him think something that isn't true.
MFing can be a lie or a BS but it always involves an element of furtive emotional manipulation which may sometimes be lacking in cases of BSing and lies. As an example, propaganda seeks to manipulate people's emotions by using falsehoods or half-truths aimed at people's deep-seated fears, biases and prejudices. Certain kinds of advertising also can be understood as perfect examples of MFing. McGinn also gives an excellent literary example from Othello. Iago seeks to implant the seeds of mistrust and jealousy in Othello knowing full well he has a tragic flaw: he is susceptible to bouts of rage and jealousy. Iago does this using deceptive insinuations and half-truths.
Where I felt McGinn's essay was somewhat wanting and unconvincing was in the very speculative last section called, "Extending the concept." McGinn here claims that the less alternative information is available in a society, the more MFing will the people in it be subjected to and the more susceptible they will be towards its effects. While there certainly is some truth to this, McGinn makes a quantitative statement about the amount of diversity in viewpoints publically available while leaving out what, I think, matters even more. And that is the differences in effectiveness or quality (in persuasiveness) of the different viewpoints which are available. You can make two alternative competing viewpoints on some subject widely and equally available but if one of them is far better advertised i.e., is far better at persuading people through emotional manipulation, it will be the message that people take into account while they ignore/dismiss the other viewpoint.
Now McGinn might concede this point but he makes no mention of the degrees of effectiveness of the messages in competition with each other, just their relative amount. Take the D.A.R.E. anti-drug use campaign. It was widely advertised during the 80-90s and D.A.R.E. programs well funded but there is no evidence they worked that well in curbing childhood substance abuse. Children are MFed by their peers, for example, into drug use many times through things like peer pressure or shaming them despite the constant din they are surrounded by at school and on TV of an alternative say-no-to-drugs message.
Overall, I'd say this booklet was entertaining and insightful though not nearly as much as its inspiration, "On BS," which is a classic. The essay is highly readable (I read its 76 pages in two sittings, quite rare in a work of philosophy), entertaining and, as you might expect, sometimes humorous.