A:Answer They are selling the hardware, and Ooma is providing the service for free, via the internet. But, yes, you're right that you still need to connect a hardware phoneset.
But, it is pretty unique, and there's really no other category for Best Buy to put it in.
I highly recommend the product/service because you don't have to deal with a landline phone company, and there is no charge except government mandate fees which you would otherwise pay to the phone company, anyway.