(FORTUNE Magazine) – You've probably watched a video news release on TV and never even known it. These one- to two-minute tapes resemble original reporting by a news crew. But companies produce them to display their products and then pay Medialink of New York City an average $5,000 to transmit them via satellite to TV stations around the U.S. and count the viewers. Some 99% of releases end up on the tube as news. The stations get free material and the companies publicity that's cheaper than advertising -- and maybe more effective.. Some of 1990's most-watched tapes, with viewer numbers shown in millions: -- Star-Kist announces new ''dolphin safe'' tuna (81.2). -- NutraSweet introduces its fat-free frozen dessert, Simple Pleasures (54.1). -- Disney celebrates Disneyland's 35th birthday (25.3). -- McDonald's opens in the Soviet Union (21.8). -- L.A. Gear previews a TV ad campaign (21).