"Over time, users wind up paying Comcast significantly more money than the modem or router is worth." It's not really the cost, probably for 90% of users, it's

"Over time, users wind up paying Comcast significantly more money than the modem or router is worth." It's not really the cost, probably for 90% of users, it's more your average soccer mom doesn't want to deal with owning, updating, and maintening networking gear. So the service has some value to people.