I purchased one last November as an alternative to a landline phone.
It goes into the USB on the pc and as long as the pc is on and the internet is up and running- you have phone service.
I swore by MagicJack and raved about it...until I started hearing beeps....like someone one the other end was pressing buttons like touch tones or something. I did some research and found it was normal and felt it was worth free phone service....until the people I talk to tell me to "say that again, I can't hear you ....you are pressing your key pad" or "repeat that, you are accidentally hitting your buttons".... I am not. So they are hearing the beeps.
magicjacksupport dot com is a place I go for tech support and so many complain about it. So, I won't renew...it's so embarrassing.