I'm a fan of The Challenger Sale, The New Solution Selling and all three books by Jeff Thull: Mastering The Complex Sale, Exceptional Selling and The Prime Solution. I really like Thull's approach, especially his "always be leaving" mindset, as opposed to the old "always be closing" idea. Thull's thinking is much more focused on providing an authentic and honest experience, and genuinely trying to help the customer - as opposed to stuff about how to "trick" the customer into saying yes. I also like a lot of what I've read from Jeffrey Gittomer and Grant Cardone. Oh, and The Ultimate Sales Machine by Chet Holmes as well. He (Chet H.) did a series of videos with Anthony Robbins that is really good. I really recommend watching those.
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