Westlake Village-based NetZero Inc., one of the nation’s largest Internet service providers, unveiled a new television ad campaign last week it said would further blur the lines between content delivery on old and new media.

The commercials, designed to air only during the NBA finals, were produced exclusively with Web-development tools and are intended to transfer seamlessly from broadcast media to the Internet.

Promoting NetZero’s premium Internet access service, called NetZero Platinum, the advertising was created, from conception to post-production, in-house using Macromedia Inc.’s Flash technology. Flash has become the rich-media development tool of choice for Web publishers.

“Flash enables developers to create content once and deploy it across multiple media making it an ideal technology to spur convergence,” said Peter Goldie, general manager of the rich media group at Macromedia in San Francisco.

Because images are created with vector graphics, rather than pixels, Flash animation can appear as high-quality full-motion animation on television, without distortion or pixilation, he said.

Peter Delgrosso, a NetZero spokesman, said that the company’s 60-second TV spot would have cost from $600,000 to $1.5 million to produce using traditional methods. Using Web-based technology brought the ad’s production cost down to between $15,000 and $20,000.

“Simply put, NetZero spent roughly 2 percent of what it normally takes to develop television creative, making the ratio between the ad production costs and media buy incredibly attractive,” said Brian Woods, the company’s chief marketing officer.

NetZero, founded in 1997 as an ad-sponsored ISP, has 8.6 million registered subscribers. In March, the company launched a $9.95 subscription service for users who spend more than 40 hours online per month.