News flash: Some marketers think that television advertising is fast becoming less relevant. This is hardly news for some of us, but a recent survey backs up what many already sensed, giving investors food for thought when considering certain stocks.

Ever since Motley Fool Stock Advisor selection TiVo (NASDAQ:TIVO) came onto the scene, giving viewers unprecedented power over what they watch, we've all been waiting to see what the fallout would be for advertising. According to this most recent survey, conducted by Forrester Research and the Association of National Advertisers, about 70% of the companies surveyed think digital video recorders and video on demand will "reduce or destroy" the effectiveness of traditional TV ads. Among the companies surveyed were big-time advertisers like Verizon, Colgate, and Johnson & Johnson.

Last year, Procter & Gamble was reportedly ratcheting down its TV advertising budget; companies like Yum Brands' KFC have tried to come up with innovative ways to compel viewers to pay attention. Product placements and programming with embedded marketing messages are also becoming more prevalent.

And of course, who can ignore Internet advertising, particularly search-related advertising, through giants like Google? By all accounts, Internet advertising's doing well -- some even refer to the online advertising market as "frothy." Meanwhile, I haven't been able to ignore recent TV ads from General Motors, which seemed to meld the best of both worlds, inviting customers to Google its company name.

Consumer-oriented companies that have traditionally relied on advertising to help drum up business obviously have to chase the most effective -- and cost-effective -- means of getting their messages across. What will be most interesting, of course, will be how this affects the networks that have grown accustomed to having an advertising cash cow to support their broadcast and cable content.

Such disruptive changes could greatly affect related revenue streams for companies like CBS (NYSE:CBS), General Electric's (NYSE:GE) and VivendiUniversal's (NYSE:V) NBC, Disney's (NYSE:DIS) ABC, and News Corp.'s (NYSE:NWS) Fox. It's worthwhile to mention that most of these companies are conglomerates, so investors can always hope that other business lines offset any weakness. On the other hand, there's CBS, which recently parted ways with Viacom (NYSE:VIA). CBS gains 64% of its revenues from its television segment, most of which consists of advertising revenues, so "a decline in advertising expenditures" is, of course, the first on the list of Risk Factors in its 10-K.

There's no doubt that advertising is changing with the times. Keep an eye out for more innovation -- and, depending on what transpires, the impact on sales -- as related companies strive to keep up.

TiVo is a Motley Fool Stock Advisor recommendation. Colgate is a Motley Fool Inside Value selection. To find out more about our suite of newsletters, click here.

Alyce Lomax does not own shares of any of the companies mentioned.