GPS systems typically have a high initial cost of around $100,000 per machine.

Another article in the package mentions the "enormous price per machine."

You get up to $60 or $70 a week per machine.

Both these factors point to possibly greater profits per machine.

A decision was also made to apply one fewer sticker per machine.

Singer then took out a license under Howe's patent and paid him $1.15 per machine.

They later increased the number of records from 50 to 80, then 100 per machine.

"Unless the cost comes down to around $5 extra per machine, no one will put it into their machines."

Pressed to make a guess, he said: "Five to ten users per machine sounds pretty reasonable."

But that's probably going to be unique per machine.