Microsoft Rebranded Office Every 2-3 Years Primarily for Retail Sales
Microsoft rebranded Office every two to three years from the early 1990s until around 2000, and it wasn't primarily for design reasons. The real reason was retail sales.
According to former Microsoft executive Steven Sinofsky, who spent 23 years at the company, including running Office product development through six major releases, the goal was to make new versions of Office look attractive to customers so they would buy them. In those days, software distribution and pricing worked differently than they do now.
Sinofsky explained that in retail sales, a new icon and name gave Microsoft something to put on the box, in magazine ads, and on store shelves. Without visible changes, there was little reason for customers to buy new versions of Office.
Enterprise contracts also played a role in this strategy. Large customers signed three-year agreements that allowed them to deploy whatever Office release shipped during that term. But deploying a new release across an entire company was expensive and time-consuming, so Microsoft needed Office to look new often enough for customers to feel they were getting something for their money.
The year-based naming of Office versions, which started in the late 1990s, was also intended to make last year's version feel outdated. However, this idea didn't quite fit with how software distribution and pricing worked at the time.