However, a senior vice president in Microsoft's central marketing group, Mich Mathews, contended in an interview Thursday that it was always the plan to replace the Seinfeld-Gates ads with ones that focus on Windows.
"The notion that we're doing some quick thing to cancel (the Seinfeld ads) is actually preposterous," Mathews said. "Today was always the day. ... Media buying is something you have to do months in advance."
Mathews described the three Seinfeld spots as ice breakers with a limited shelf life, designed to grab people's attention in a tongue-in-cheek way without the pressure of having to talk about the product.
"We wanted to be sure that when we do come out with our major message, today, `Life Without Walls,' more people would be paying attention than they would otherwise," Mathews said. "My goodness, did we do that."
The Windows-focused campaign attempts to turn Apple's "I'm a Mac" ads on their head. A new TV ad set to debut during "The Office" on NBC Thursday evening begins with a Microsoft engineer who looks like the PC character in Apple's ads saying "Hello, I'm a PC, and I've been made into a stereotype." He's followed by a montage of real-life PC users, celebrities and Microsoft Windows engineers who all repeat the "I'm a PC" mantra.
Microsoft also has ads queued up for print, Web and public spaces that focus on the way Windows, Windows Mobile, Microsoft's Live services and its TV platform connect.
The $300 million campaign was designed by ad agency Crispin Porter + Bogusky. Microsoft said the company is "exploring options" with Seinfeld for new ads, but that no ads beyond the three that aired have been filmed so far.