There are certain benefits of using the Salesforce developer account:
Salesforce provides it free of cost to developers as a playground for their work
A developer account can never expire
You can experiment with certain development activities
You can share your application with peers by creating packages
The developer account comes with a number of preinstalled applications such as sales, call center, marketing, and ideas
Updates are automatically installed in your developer account; these updates include:
Salesforce customer portal
Two Salesforce CRM licenses
Two Salesforce mobile licenses
Three Salesforce platform licenses
Five Salesforce partner licenses
10 Salesforce customer portal manager licenses
The following screenshot shows the license details of the developer organization: