Conducting a cell phone service comparison is not as easy as you might think. Different companies offer vastly different service plans. For example, one company may offer unlimited night and weekend minutes while another counts all minutes equally. Other companies may allow unused minutes to carry over to the following month. Some pad their contract price with extras, like data and text messaging. Customers must take these factors into consideration when comparing different cell phone service plans since they may cost significant fluctuations in price between plans.