From the HP website:
The HP refund program is our way saying thank you for choosing HP webOS.
Subject to the remainder of these terms and conditions customers can claim the compensation amount on the qualifying HP products illustrated in the table below (the “Qualifying HP Products”) if their net purchasing price was higher than the HP defined minimum price level also illustrated in the table below and they have been activated/registrated within their webOS account before 23rd of August 2011.
HP employees purchasing the products during the EPP program will not be able to participate in this program. The offer is valid only in the UK and Northern Ireland for private end users and business customers.
Source: HP via: itproportal