I just checked. There's a kindle version on amazon :
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I bought the hard back myself
I never tried audio, I bought the hardback.
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I thought it was quite useful all around guide to sales (buyer motives, 6 Whys people buy, company USP, closing). Interesting was the use of behavioural economics and psychology to inform the different techniques (such as innoculation theory). On that topic psychology and sales, the psychology of persuation and predictably irrational are both really great reads.