Microsoft's new OS Vista "Welcome Center" screen, seen by all PC users when they start their computers, will display ads. Because that practice has caused complaints, the company is facing trouble from the U.S. Department of Justice as well as states attorneys general who are considering legal action. A report was filed last Wednesday with the judge handling Microsoft's antitrust compliance.

With millions if not billions of people viewing that screen on initial boot at least a few times a week, calling it prime advertising real estate is an understatement. While TV has died as a mass media, Microsoft's "Welcome Center" will cause marketers to drool over its reach but cause extreme concern among those who feel Microsoft will use the space to promote the company's own products.