Jim McKelvey, co-founder of Square and author of The Debugger's Handbook, joins Guy Raz to discuss how a failed glass art sale led to revolutionizing credit card payments. McKelvey, a former glassblower and early internet entrepreneur, partnered with his former intern Jack Dorsey (Twitter co-founder) to create Square's iconic card reader in 2009.

The conversation explores McKelvey's unconventional path from writing programming textbooks as a college freshman to building a multi-billion dollar payments company. He details how personal tragedy shaped his entrepreneurial drive, the technical challenges of creating hardware that worked with iPhones, and Square's survival against Amazon's competitive assault in 2014 through what he calls an 'innovation stack' - a concept he later explored in The Innovation Stack.

From Spite Book to Programming Success

McKelvey wrote The Debugger's Handbook as a freshman at Washington University after criticizing his computer science professor's expensive, poorly written textbook: 'I was indignant about that... I was saying that, you know, I could write a better book than this piece of crap.'

The book compiled programming tricks and workarounds for early language implementations, earning McKelvey thousands of dollars and establishing his reputation as a skilled programmer despite being 'not particularly great' at coding.

After graduation, McKelvey chose glassblowing over corporate consulting, rejecting a job with 'method one' - a massive binder system that eliminated the need to think: 'I can't do that.'

Personal Tragedy Shapes Entrepreneurial Drive

McKelvey's mother committed suicide on December 18, 1989, when he was 24: 'My mother's suicide was so well planned that nobody could have caught her or stopped it... She planned it.'

The tragedy fundamentally changed his approach to action: 'Part of me knew that mom was in trouble and that I could have done more. And I didn't... when I find myself in a situation where I think something needs to be done, I no longer sit there and say, well, someone else will probably do it.'

The loss motivated McKelvey to abandon what he saw as mediocrity across three businesses, focusing instead on building something significant in the computer industry.

Meeting Jack Dorsey and Building Mira

McKelvey met 15-year-old Jack Dorsey through his mother's coffee shop during a crisis at McKelvey's document imaging company Mira, where Jack helped scan materials all night.

Mira pivoted from competing with Adobe Acrobat to creating trade show CD-ROMs, charging companies $10 per page to include their literature: 'I made 70 grand' on the first trade show despite legal challenges.

When McKelvey saw the internet would kill CD-ROM business, only Jack Dorsey listened to his pivot strategy: 'The only person who would listen to me was Jack Dorsey.'

The Square Idea: From Failed Glass Sale to Payment Revolution

McKelvey lost a $2,000 glass faucet sale because he couldn't accept American Express, leading to the Square concept: 'I look at my iPhone and my attitude towards the iPhone was it was this magic device that should become anything I wanted it to... And it didn't turn into a credit card reader.'

The credit card industry excluded small businesses, requiring $100,000+ in transactions to justify the costs and complexity: 'The system was built for merchants who had $100,000 or more in transactions. It was never designed to serve a little guy.'

McKelvey insisted on hardware to achieve 'card present' status for lower fees and fraud protection, overruling Jack's software-only approach: 'You can scan your card, but you don't get card present protection.'

Technical Innovation: The Headphone Jack Solution

Apple's dock connector required expensive licensing and chip purchases, plus they restricted power-draining accessories due to poor iPhone battery life.

McKelvey found inspiration in Make Magazine's first issue showing a cell phone credit card reader hack through the microphone jack, avoiding Apple's restrictions entirely.

The original aluminum reader failed because it conducted Jack's heartbeat: 'Because he was holding it, and because aluminum is conductive, and because Jack has a heartbeat, it was picking up his heartbeat, and the heartbeat was screwing up the reed.'

The final reader cost 97 cents to manufacture and fit in 'that little pocket in your jeans that nobody knows what to do with,' creating a magical user experience despite technical limitations.

Regulatory Challenges and VC Strategy

Square violated 17+ regulations initially, from banking rules to network requirements: 'There were so many rules... Some of them were laws, some of them were network rules, like OFAC, KYC.'

McKelvey's '140 reasons why this business will fail' slide transformed VC meetings from adversarial to collaborative: 'We changed the entire tenor of the room by saying, look, here's all the stuff that we don't know.'

VCs responded by offering help rather than playing defense: 'Most of the VCs looked at our list and said, Well, we can help you with that one.'

Surviving Amazon's Attack Through Innovation Stack

In 2014, Amazon launched a competing payment reader with lower fees, prompting McKelvey to research companies that had beaten Amazon as startups: 'I found none.'

Square's strategy was to ignore Amazon entirely rather than engage in a price war they couldn't afford: 'We decided to not do anything.'

Amazon's product failed because they only copied 3 of Square's 14 innovations, missing what McKelvey calls the 'innovation stack' - the complete system of interconnected solutions required for true innovation.

Amazon eventually gave up and mailed Square readers to their customers, demonstrating how copying surface features without understanding underlying systems leads to failure.