Do customers need to monitor their cell phone bills

I feel Yes. It is very important to pay attention to your monthly cell phone bill because most are structured in such a way as to incur steep overage fees if you go over the amount of time you pay for each month, or use features which operate on a pay-per-usage basis. For someone who is used to a home phone line in which only long distance numbers cost extra, this can be a startling and often expensive realization.

What do you guys think about this?