Large publishers, such as Washington Post, have recently started introducing their own native advertising formats.

For all involved, except the viewers,the participation format proved to be a far more beneficial advertising format.

Outdoor advertising formats fall into four main categories: billboards, street furniture, transit, and alternative.

Mr. Hoeber agreed that they were not in an "advertising format."

And Yahoo, like other online media companies, allowed advertisers to have bigger, more interactive advertising formats.

"Banners are just like other advertising formats," he said.

But in the last few years, Web sites have created bigger, more interactive advertising formats and marketers have learned how to use them.

In the United States, the success of this advertising format eventually led to the growth of mail-order advertising.

But larger, animated advertising formats have helped Yahoo win business from big brand advertisers like car companies.

While these alternative advertising formats are gaining momentum, they represent a small portion of the advertising market.