Yahoo CEO Terry Semmel's decision to cut his $1 billion offer for Facebook to $800 million after a stock dip caused a young Mark Zuckerberg to walk away from the deal. The move, intended to save Yahoo money, backfired spectacularly and is a key lesson in deal-making psychology.

Accepting too high a valuation can be a fatal error. The first question in any subsequent fundraising or M&A discussion will be about the prior round's price. An unjustifiably high number immediately destroys the psychology of the new deal, making it nearly impossible to raise more capital or sell the company, regardless of progress.

In deal negotiations, reducing an offer price is a delicate matter. While "retrade" and "haircut" both mean cutting the price, they have different connotations. "Retrade" implies a broken promise and aggressive tactics, while "haircut" sounds more reasonable and justified by new information found during diligence. The choice of word is a key part of negotiation framing.

In M&A, the closer you get to closing, the more emotionally invested you become, even mentally spending the money. This attachment makes founders vulnerable to accepting last-minute unfavorable changes because they've already "emotionally bought in" and moved on from owning the company.

Zayo CEO Dan Caruso would sometimes counter a seller's offer with a lower number than his previous bid. This unorthodox move was designed to create emotional distress, reframe control, and break a negotiation stalemate.

A deal with two founders was about to sign when the less-committed founder hired an independent valuation firm. The firm provided an unrealistically high valuation, which he used as justification to kill the deal. Acquirers should address founder reluctance early, as emotional attachment can override a logical deal process.

Instead of lowballing, Bending Spoons makes a very fair, near-final offer immediately. This tactic builds a reputation for seriousness, similar to Warren Buffett's approach. It avoids lengthy back-and-forth and signals that they are not a buyer that can be "pushed around," creating an efficient and powerful deal-making process.

The strategy of setting an artificially high price to negotiate down is dangerous in an era of high transparency. When customers inevitably discover they paid more than peers, it destroys trust and reputation. Maintain a consistent price, offering flexibility only through standardized commercial levers.

In a public company M&A battle, the fight extends beyond the offer price. The Paramount camp actively messages how Netflix's stock has dropped since the deal was announced, attempting to create shareholder pressure that prevents Netflix's board from increasing its bid.