Only in case of Drupal development customers get:

* a web-site build on the safe system which is based on open source code, the system which is tested by million users all over the world. professional content management system;
* it is more likely that possibilities of Drupal system are limited by developer’s imagination rather than facilities of Drupal itself; this will be a web-site with great performance and scalability;
* confidence that CMS producer won’t disappear;
* web-site with moderate price even if there is a need in development of some specific features which are not developed in Drupal yet;
* new versions of Drupal core and its modules are available for free.