They need to get traffic to their site quickly, no matter what it costs. Let's reflect on what they are trying to accomplish and whether the Internet might provide better ways of doing it. Direct mail is a bit different, because you can, if you wish build your own list. But in most cases, advertisers rent lists or include their messages in the mailings of others. Traditional marketing, typically, neglects the substance.
Marketers presume that products and services are developed or chosen by other people in the company.
Their job is to get the message out, to bring the products and services to the attention of the target audience. In some cases, their campaign might include events, contests, and offers that have little or nothing to do with the substance but have been created solely to draw attention to the message and motivate the audience to act now. They might also equate marketing over the Internet with the creation and placement of banner ads, since that's the form of marketing most likely to get their attention first. And just as they turn to ad agencies to help them with ad creation and placement for radio, TV, and print, they turn to the same agencies for help here. They may even know about specialists they can turn to for help putting together games, contests, and gimmicky offers.