Salesforce is an awesome CRM application.   And the first ten licenses for Salesforce for Nonprofits are free.  It's a great offer but isn't always the right solution for a nonprofit.

Salesforce is successfully used by the biggest non-profits but smaller organizations can struggle with the need for consultants to implement common requirements.  CiviCRM along with Drupal provide more extensive "out of the box"  capabilties for non-profits.   Also, the CiviCRM data model has been developed specifically for non-profits and can be more intuitive even for some fairly complex requirements.   

Last, but perhaps most importantly, if your goal is to integrate your data management with a website, CiviCRM and Drupal provide unmatched capabilities that do not require custom coding or API based integration.  A demonstration of these features is an eye-opening experience.

Nubay has worked with clients that have started with Salesforce and needed another solution.    We'd be happy to discuss your experience and answer any questions.