People like LeBron James and Taylor Swift make most of their money from endorsements, and I&#x27;d argue that endorsement income doesn&#x27;t really scale very well. There&#x27;s a limit to what your brand is worth if you&#x27;re a celebrity - you can make hundreds of millions of dollars by diversifying across a huge range of products but that&#x27;s pretty much it. You&#x27;ll never earn more than a small percentage of the marketing budget of the biggest company in any one market multiplied by the number of markets your celebrity brand is applicable to. Whereas a tech founder has a practically unlimited upper bounds to their net value; if you start a company that becomes the defacto monopoly in a space (operating systems and office software, or social media for example) your fortune tops out at some percentage of that entire market, multiplied by the number of markets you can leverage your product in to. That&#x27;s a far bigger number.