37 Signals talks extensively about the Cost of change. One of the goals of Jumpchart was to not impede change. Several things happen during a normal web development process.

• Content needs to be found or created, and tagged to appropriate pages in a site
• Sections need to have names
• Sub-sections need to be added to contain additional info

Inevitably:

• Content is found or created late in the process
• Content needs to be moved, or deleted
• Top-level nav needs changed, added to, or deleted
• Sections become sub-sections, and vice-versa

In all cases Jumpchart forces no penalty for the inevitable revisions. Moving, reorganizing, and changing content is a quick-click process.