2-minute expert: How much smartphone data do I need?[ Sat, 24 Mar 2012 16:48:28 GMT ]If you have a smartphone, you have to buy a data plan as well, which could add around $360 a year or more to your bill. Wireless carriers have implemented new pricing, data limits and "throttling" that can make figuring out plans downright baffling. Here's a handy chart to help sort it all out.