PORTLAND, Ore. (AP) _ Gardenburger took a huge gamble in spending a wad to promote its veggie patties on the show about nothing. It seems to be paying off.

The tiny company spent about $1.7 million for a 30-second ad on the final episode of ``Seinfeld'' on May 14, and since then its sales have exploded.

In the week following the ``Seinfeld'' finale, Gardenburger sales jumped to nearly $2 million, up from $368,000 in the same week a year ago, according to Nielsen scanner data from around the country.

``The results have been terrific,'' Gardenburger CEO Lyle Hubbard said Wednesday. ``All we did with our advertisements was to say, `How can we get the most people to try it in the shortest period possible?'''

The strategy posed more than a little risk for a company that did just $57 million in sales last year. Its half a minute in the ``Seinfeld'' spotlight was the crown jewel of a five-week television campaign costing $15 million _ its entire ad budget for the year.

But with the apparent success, Hubbard said the company is now looking at extending a campaign, which was supposed to end later this month, throughout the crucial summer grilling season.

``These ads are far from being worn out,'' Hubbard said. ``People like these ads _ they're fun.''

Gardenburger's spots _ which have also been airing on ``ER,'' ``Touched By An Angel'' and ``Oprah'' _ are retro-style cartoons showing people pushing away meat to munch on meatless burgers. Actor Samuel L. Jackson is the voice on the tag line: ``Eating Good Just Got Great.''

Hubbard credited the ads with not only helping Gardenburger, but the entire veggie patty business. Meatless burger sales totaled $3.8 million for the week ending May 23, compared with $1.8 million during the same week of 1997. And Gardenburger's share of the market jumped from 20 to 50 percent.

Marian Freistad, a marketing professor at the University of Oregon, said the question now is whether Gardenburger can sustain what could turn out to be only a bump in sales.

``I like Gardenburgers and I buy them, but not everybody likes them,'' she said. ``And if people don't like a product, they won't buy it again, no matter how great the advertising is.''

Hubbard pointed out that people have been enjoying Gardenburgers since 1985, mostly in restaurants and cafeterias, and this was the company's first major push to make them commonplace on grocery shelves.

``Clearly, we expect to get the repeat business,'' he said.