Critics conclude that entertaining or "creative" commercials sell better than those that are bland. But liking the commercial may not really be that important in the scheme of things. It all depends on the needs and preferences, motivation and financial reservations of the customer. The question isn't whether people like the advertisement or not, it's whether the advertisement is effective in selling.

Often, people who are irritated by certain campaigns don't fall within the intended target market. In 2000 Budweiser ran its ''Whassup?!'' campaign. Ad Track reported these commercials scored best with 18- to 24-year-olds; 52% of the survey participants said they liked them ''a lot'', while participants 65 years old and over didn't understand them, or didn't want to; 61% disliked the commercials. Yet, it's highly unlikely that Budweiser was trying to reach the 65+ market.

When Toys R Us launched their campaign featuring Geoffrey the giraffe to promote the revamping of all Toys R Us stores, 38% of women rated the advertisements highly compared to 16% of men. Since the advertiser's goal was to get moms back into the stores, that low rating from men was meaningless to Toys R Us.

Pier 1 started running its commercials featuring Kirstie Alley this year. Twenty-seven percent of the people familiar with the commercials didn't like them, and only 6% thought that they were effective. That comes as a surprise to Pier 1 because same-store sales rose 17% in February and foot traffic is up 12% since October! The goal of most advertising is to increase sales. So, if people buy, the advertising is effective-no matter what critics may say.

Let's look at some other factors that contribute to the effectiveness of "irritating" or "disliked" advertising. Media weighting has a lot to do with response to advertising. It's important the media plan is developed to accurately reach its target. Just the right amount of frequency has been proven to increase recall, recognition and even persuasion. So a focused and targeted media schedule with effective frequency is a major influence in selling a product.

Familiarity with the product plays a role in increased sales of a brand with an "irritating" advertising campaign, too. According to the Journal of Advertising Research, customers' knowledge of, experience with, or loyalty to a brand are components of familiarity-and familiarity is the most important factor in the effectiveness of advertising. Since customers tend to give greater attention to advertisements of a familiar brand, and may attach their experience with the brand to the advertisement, customers are likely to accept the message and respond to the "irritating" advertisement with a purchase.

International Brand & Advertising Research conducted a test to determine if "feelings of liking or disliking commercials are the motors that drive brand attitudes and sales." In the study, 251 30-second commercials were aired, representing six major product categories: food, confectionery & desserts, beverages, household products, personal care products and automotive. An analysis of the 251 commercials showed that there was no "robust, empirical evidence to suggest that either liking or disliking are reliable predictors of a commercial's performance in relation to sales-validated, evaluative measures." In fact, liking or disliking accounted for "no more that 11% of the variation on any of the major evaluative measures."

A "well-liked" advertising campaign does not always mean an increase in sales. Just like an "irritating" advertising campaign does not always suppress sales. The fact of the matter is that effectiveness depends on factors other than "likeability", and what may be "irritating" to some may not be "irritating" to the intended target. At the same time, what may be "well-liked" by one group may not be received as well by another. It's up to the advertiser to determine the most likely target and the best way to reach that market to make a campaign effective.

Mark Levit is managing partner of Partners & Levit Advertising and a professor of marketing at New York University. Partners & Levit's clients include Procter & Gamble, UnitedHealth Group, and GE Commercial Finance. For more information call 212-696-1200 or visit http://www.partnerslevit.com.