Does the Web affect consumer perceptions on the quality of various products before and after purchase? To answer questions on quality perceptions in traditional sales channels, researchers use a classification of products proposed by Nelson (1970, 1974) and other researchers on search, experience and credence (SEC) goods. This classification is very useful in evaluating market structures and advertising effectiveness in economics and marketing studies. Since the Web became a popular medium for shopping, how has the availability of Web decision aids changed the perceptions of consumers on the SEC product categories? A pilot study shows that credence and experience products become closer to search products, while search products can exhibit more search attributes for online purchases. In addition, consumers seem to feel less, not more, certain about what they know on products when they use both the Web and non-Web decision aids. Implications and future research plans are discussed.