- Adweek Staff

NEW YORK Video data is the prime mover behind big increases in Internet bandwidth usage.

The current increase of high-quality, long-form video content (TV shows and full-length movies) -- the type of high-bandwidth content necessary for substantial online video ad growth -- would hit major roadblocks under changed ISP service plans. Several ISPs are looking to limit their customers' bandwidth usage.

The problem could spill over to online video and its associated advertising.

At stake is the U.S. online video ad spending market, which is expected to nearly quadruple from $505 million this year to $1.9 billion in 2011, and will triple again two years later to $5.8 billion, according to eMarketer.

If people need to pay extra for additional bandwidth or are threatened with slower service, many will have qualms about watching too much free video with advertising alongside.