Don: The free account comes with every upload-enabled weather station (IP-100), and provides real-time data, data archiving, and export of archived data in a pre-determined format.
RW is currently working on a paid Pro Account (as low as $4.49 a month) - (Coming Soon)
A Pro account provides all the above PLUS visual graphing of data, email and SMS text alerts, a report generation engine, and enhanced exporting of data in several formats.
Rates for the Pro account:
Monthly: $5.99 per station Annual: $4.49 per month per station (total $53.91) Save 25%!