*If you don't have SMS forwarding enabled.
Google doesn't bill you for minutes for voice calls but they do count against your voice plan minutes. I wouldn't exactly refer to voice calls as free.I belive everything from from google voice is free...
Who said that Google Voice calls are counted against your Verizon minutes? As far as I know, Google Voice uses airtime data to make phone calls, the same way like Skype does it. Therefore, I believe it doesn't use the minutes and theoretically you can have unlimited minutes if you call through google voice. Unless I'm wrong?
GV calls are made by calling a number. If you have a plan were you can call certain number for free, and you put that number (and the number google uses to send you GV calls) then they don't use your call minutes. However, if you don't have one of those plans, (or do have one and don't put the GV numbers into it), then you use normal call minutes.
And, I've read that the numbers that GV uses do change from time to time, so it's good to check them and update your favorite numbers.