This information applies only to Economy Plus customers Huntsville and Mobile, AL; Atlanta, Augusta and Savannah, GA; Central Kentucky; Maine; Jackson, MS; Knoxville and Memphis, TN; and Charleston, SC, who choose to participate in the Flexible-Data Option.
If you choose the Flexible-Data Option and you use 5 GB or less in a particular month, then you would not be subject to any additional charges. This monthly option is designed for those Economy Plus customers who are casual or light Internet users.
If you anticipate that you would or could use more than 5 GB in any particular month, then this option is not the right choice for you in that month. Here is a tool to help you estimate your data usage: http://xfinity.com/datacalculator.