The paid account has an unlimited retention period.  Addionally, you may downgrade your account back to a free account at any time, but the current month's charges will still apply.

Registration 
Login  Level:
Password
Email
Plan ID
Billing Information
Credit Card First Name
Credit Card Last Name
Credit Card Type
Credit Card Number
(Only last four digits displayed after entry)
Credit Card Expiration (mm/yy)
Credit Card City
Credit Card State
Credit Card Zip
Credit Card CSV