Verizon has spent billions of dollars to upgrade its network from 3G to 4G.But there aren't that many 4G-compatible devices, coverage is spotty, and most applications don't really need higher speeds. Verizon is hoping that its investment in 4G works out.

Based on the potentially slow initial adoption of 4G by customers, how might the conclusions of a cash payback analysis of Verizon's 4G investment differ from a present value analysis?