Why do you need a landline? Don't you have a mobile?
I know people who do this. Total pain. Reception is not great. The call crackles in the way a landline doesn't. Lots of people are still not on contracts and so ringing a mobile is a higher cost, particularly for people who have landline bundles making landline to landline calls free of charge. It will probably be the future but we are not quite there yet. Don't also forget that most broadband is also currently done through a landline.