Frank Harper is well aware that all those free video clips on the Web 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 protection 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 Net 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 all Net 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 — particularly 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 with which the ads seem — so visitors notice the pitches without getting so annoyed that they never come back.

“Users love free substance 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 advertising 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 yet.”

The results so far 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 go it ahead or further along,…

Orginal post by Top Tech News