You're exactly right, we think the target market is older and less comfortable with technology than the Hacker News crowd. The most common reaction we get when we pitch the service to someone is "I wouldn't need that, but it could be great for my parents/grandparents/inlaws/etc". Ideas about how to best appeal and market to this demographic are welcome.
If my inlaws wanted to get rid of their landline and get individual cell phones and needed their old number to transfer out, they wouldn't port their number to Google Voice and then forward from Google Voice to their cell phone.
I'm also not sure if paying $10 / month is attractive to consumers, but that's just speculation!