When I was a computer technician for a very large company in the mid 90s, you would not believe how much porn I saw on peoples work computers and they were always complaining about needing a bigger hard drive.

Last thing I listened to was Technology Connections, doing their long-format series on the format wars. According to him, porn haven't played a major role. He highlighted that the beta tapes of the time were shorter and the players a bit more expensive, than the VHS system. Because of this, VHS players sold more, so the market was bigger, so the catalogue, including porn, was bigger as well.