"Selling the Dream," the "Smithsonian World" TV special airing tonight on Channel 26 at 9, is a level-headed and serious look at the advertising business. That's its problem -- it's a little too proper, especially given the vivid nature of its subject. You'd like it to tear into the thing, juices dripping. Instead, it nibbles daintily.

Produced by WETA and the Smithsonian, "Selling" has a promising come-on. By deftly using material from the Smithsonian's advertising history archives, it provides a brief overview of 20th-century advertising's Big Idea: the exploitation of emotion, instead of logic, to persuade and sell.

This is a potentially rich vein, but "Selling" doesn't dig deep. It rightly points out that advertising's power derives from its ability to tap into deep psychological currents -- vanity, fear, the need for love and status (and sex; the program, astonishingly, ignores sex). For a nation coming into wealth and power, advertising in the early part of the century taught "not only what to buy," as narrator Susan Stamberg informs, "but how to live, how to be modern."

Yes, right, so how about that? How has advertising shaped or reinforced -- dare we say perverted? -- our image of ourselves and each other in the name of moving the merchandise? Apparently, it just has.

At one point in the hour-long program, two scholars suggest a promising avenue -- that advertising has perpetuated racial stereotypes by repeatedly presenting blacks in familiar endorsement roles (as entertainers, servants, athletes etc.). Instead of looking for itself, "Selling" weasels out by pitching the question to a couple of ad executives from Nike, who politely decline to take the blame.

At least it's still fun to watch some old TV commercials.

A good chunk of the program is devoted to a documentary-within-a-documentary about the making of a contemporary commercial, in this case Grey Advertising's exertions in behalf of its sports car client, Mitsubishi Motors. These segments offer some lively details about the process of making ads, such as a visit to a recording session (wherein a weary producer tells the commercial's voice-over narrator: "You gave me philosophical, but sort of drawing-room philosophical. I need broadcast philosophical!"). Collectively, however, these portions absorb too much time illustrating only a semi-interesting point: that advertising is a painstakingly crafted, deadly serious business.

For all its limitations and missed opportunities, "Selling the Dream" displays a greater intelligence than "Sex, Buys and Advertising," the overheated and superficial documentary NBC aired last summer. Yet it isn't nearly so eye-opening as the subversive "Buy Me That," a 1989 HBO special about children's advertising.

As is, "Selling" violates a cardinal rule of advertising: It isn't memorable. There's not enough sizzle here, nor enough steak.