Having been developing exclusively on Salesforce.com for the last 3 years, I can say it is my preferred platform!  As a solution for non-profits, I believe it has many great benefits:

• 10 free enterprise licenses (worth over $15,000 a year)
• Remotely managed by Salesforce, so your data is safe, secure, and backed up.
• A system that can grow to handle many different needs in the non-profit, including donor management, volunteer management, email lists, client lists, service tracking, etc.
• A 3rd party marketplace, AppExchange, that provides additional applications such as bulk emailing tools, event management, auction management, website integration.  Many of which are provided at discounts to non-profits.

The features I love most as an application developer include

• I don’t have to install and help maintain software that is located at the non-profit on every staff member’s computer.  All that is needed is an internet connection and a browser.
• I don’t have to spend lots of time creating forms and pages for each new piece of functionality I add to the system – all the pages are consistently provided by Salesforce.
• Common subsystems and applications I create can be packaged and shared between non-profits.
• Salesforce continues to add new features and evolve the system, while always maintaining strong support for older applications.

I still fret that the reporting tool built into Salesforce is not as powerful as Microsoft Access.  But I am hopeful that it will continue to improve, and I know there are more 3rd party tools that make reporting easier.  Luckily, lack of reporting has not been an issue for any of the solutions I’ve created with Salesforce so far.