Frank Harper is well aware that all those free video clips on the Internet come at a price: advertising.
But that doesn't mean he sits idly as short video ads precede many of the dozen or so clips he watches each day at sites like Microsoft Corp.'s MSN.
"For the most part, I just mute the volume," said Harper, 55, who runs a security consulting firm in Sterling, Va. "Or I just look at something else, look at another headline … or go to another site while the thing is playing."
Marketers and Web sites alike are struggling to bring to the Internet ads that resemble television without turning off viewers the way TV ads often do.
Spending on online video ads represents less than 4 percent of Internet advertising and just 1 percent of the amount spent on TV, according to eMarketer. But growth is expected — with the research firm forecasting U.S. spending more than tripling to $4.3-billion in 2011 — especially as more viewers embrace full-length TV episodes and other video online.
The challenge is finding the right formula — in the creative approach, the format or the frequency — so visitors notice the pitches without getting so annoyed that they never come back.
"Users love free content and advertisers love to fill up every minute and pixel with the messaging, and publishers do have to find that balance," said Geoffrey Coco, an ad executive with Microsoft, which has a video news partnership with the Associated Press. "There's been a lot of innovation but I don't think we've settled down."
The results have been mixed — even when sites force viewers to watch video ads by making them impossible to skip. Viewers "are grabbing the status bar, trying to click it ahead or further along, and while they are figuring out how to skip the ad, they've missed the ad," said Jonathan Sackett, chief digital officer with the Arnold Worldwide ad agency.
And some studies have shown that many viewers abandon the video if an ad appears. Yankee Group senior analyst Daniel Taylor said sites that insist on "no ad, no video" risk losing frustrated visitors to rivals forever — along with future ad opportunities.
Google Inc. and other search companies have generated billions of dollars from text-based ads that appeal primarily to merchants seeking a direct response, such as an immediate sale.
But for companies more interested in longer-term brand promotion, video could make a much more lasting impression.
"It's emotive, rich. It grabs your heart," said Suranga Chandratillake, founder of video search company Blinkx PLC. "It combines all that is great about TV advertising with all that is great with online advertising" — the ability to more accurately track who's watching, when and for how long.
Although many advertisers are simply repurposing television ads as online "prerolls," a few are trying to break from that mold with ads that are more interactive.
During a recent episode of Lost on ABC's Web site, for instance, Taco Bell offered a virtual photo shoot with Sports Illustrated swimsuit model Daniella Sarahyba.
Meanwhile, Google's YouTube and Time Warner Inc.'s AOL have introduced "overlay" ads at the bottom of selected video clips. Clicking on an overlay pauses the video and launches the full pitch, such as a preroll or movie trailer. The overlays disappear after several seconds if the viewer does nothing. Yahoo Inc. plans a similar offering this year.
Industry experts say alternative formats could work best with shorter clips, the ones popular on YouTube. After all, who wants to watch a 30-second ad just for a 15-second clip?
Advertisers, though, will have to figure out how to get people to click.