He may have "made it up" to improve sales, but from a certain viewpoint it's correct. If decide to measure the "value" of a network based on the number of node connections, then the number of connections for n nodes is n(n-1)/2 = 0.5n^2 - 0.5n which is O(n^2).
Of course, the value of something is hard to measure. Typically you measure value as "benefits - costs", and try to convert everything to a currency. E.g., see: https://www.investopedia.com/terms/c/cost-benefitanalysis.as... . But there are often many unknowns, as well as intangible benefits and costs. That make that process - which seems rigorous at first - a lot harder to do in reality.
So while he may have "made it up" on the spot, he had a deep understanding of networking, and I'm sure he knew that the number of connections is proportional to the square of the number of nodes. So I suspect his intuition grabbed a quick way to estimate value, using what he knew about connection growth. Sure, it's nowhere near as rigorous as "benefits - costs", but that is hard to really measure, and many decisions simply need adequate enough information to make a reasonable decision. In which case, he both "made it up" and made a claim that you can justify mathematically.
Of course, the value of something is hard to measure. Typically you measure value as "benefits - costs", and try to convert everything to a currency. E.g., see: https://www.investopedia.com/terms/c/cost-benefitanalysis.as... . But there are often many unknowns, as well as intangible benefits and costs. That make that process - which seems rigorous at first - a lot harder to do in reality.
So while he may have "made it up" on the spot, he had a deep understanding of networking, and I'm sure he knew that the number of connections is proportional to the square of the number of nodes. So I suspect his intuition grabbed a quick way to estimate value, using what he knew about connection growth. Sure, it's nowhere near as rigorous as "benefits - costs", but that is hard to really measure, and many decisions simply need adequate enough information to make a reasonable decision. In which case, he both "made it up" and made a claim that you can justify mathematically.