$CSCO required customers to buy extensive support and this was contractual (SmartNet) and this also acted like CUDA a bit - it made each CISCO router a huge investment, and a customer would lose all that support,, certifications, etc. These were real switching costs - my best friend worked for Cisco in this area at the time, and I heard all about this in real time. It was not also not so quickly commoditized. #CSCO was dominant for about a decade, and increased revenues 4x over the following 15 years while ...