Actually there's something interesting I found in the EULA.
"2. Transfer of the License. You may make a one-time permanent transfer of all your rights to install and use the Software to another individual or legal entity provided that: a) the Technical Protection Measures used by the Software supports such measures; b) you also transfer this License and all copies of the Software; c) you retain no copies of the Software, upgrades, updates or prior versions; d) the receiving party accepts the terms and conditions of this License; and e) you remove your account, if previously created, at www.thewitcher.com and revoke code used to start that account. Such transfer may not include access to any online feature, service or functionality, or right thereto, unlocked or downloadable content, dynamically served content and other online features and/or services that require with the enclosed access code, that are limited to one user account and/or that are otherwise non-transferable. CDProjekt may require that any end user of the Software register the Software online as a condition of use and/or purchase additional Licenses."