If a person has an iPhone, why pay the carrier $20-$30 a month for a second line? Just tether to the iPhone and it works as well as any built-in modem. For an iPad it probably makes sense, but not for a laptop when other connections options exist. Even with owning an iPad when I want to connect the iPad to the internet, I still use my iPhone. It is just as convenient and I do not want to pay the carriers any more than I have to pay. My $30.00 a month unlimited plan with tethering works just fine.