Today, when I came back from office and checked may account i had recievd an email containing text,

“Dear Google Earth Pro User,

Thank you for downloading a trial version of Google Earth Pro. We’d like to
offer you $100 off Google Earth Pro 4. Subscribe to our professional tool for
$300 $400 by Friday, March 14th.

Save $100 online - enter promo code PRO1L8

Username: XYZ and License Key: XXXXXXXXXX

Google Earth Pro 4 now includes:

  • Fastest Google Earth performance
  • Software upgrades included
  • High-resolution imagery updates included
  • Movie capabilities for creating virtual tours
  • High-resolution saving and printing capabilities (4800 pixels)
  • Annotation tools (draw polygons with height)
  • Measurement tools (square feet, mile, acreage, radius, etc.)
  • Spreadsheet import, ingest up to 2,500 locations by address or lat/lon
  • GIS data import capabilities, ingest parcel, demographic and 3D building data
  • Technical Support assistance (chat and email) during business hours PST

Buy a license online and receive $100 off. Select the first option and enter
promo code PRO1L8. To buy multiple licenses of Google Earth Pro 4 at this
promotional rate, contact the sales department at 866-755-2582 option 1 or
ge_pro@google.com by March 14, 2008.

The Google Earth team

earth.google.com/earth_pro.html”

There was a time when this service was being provided just for free. But with the demand of this service due to its qualities, google kept on inovating it to make it outstanding service, and to fulfill the required budgets google is now selling this service. Anyhow, it is an excelent service.