Better video quality sounds great and all, but it’s not clear there’s demand for high-definition content online yet. Akamai (AKAM), in an attempt to sign up customers for its new HD offering, is pounding the pavement itself. The content delivery network will attempt to show that HD has ready and waiting viewers by running a demo portal.

Akamai, which knows it is treading close to competing with its own customers, is launching the portal with their blessing, offering about three hours of total content from providers including Apple, CBS, BudTV, NBA, BBC, and MTV, and promising to shut the whole site down after two weeks.

Akamai VP Marketing Brad Rinklin told NewTeeVee in a phone interview he expects some 10 to 20 percent of the audience served by Akamai to have fast enough connections and processors to handle HD, but he pointed out that even if the audience is small, its affluence should be attractive to advertisers.

Unfortunately, when I tried to access the test portal from a T1 line with a MacBook Pro, I was told I had insufficient bandwidth. Rinklin joked that even at Akamai HQ in Cambridge, connections are occasionally too slow. He was well aware of the irony. The test portal still allowed me to load content, however, and the video stream — whatever quality it was — looked stunning.

Rinklin said the portal, which features advertising only from Akamai partner Verizon, will be promoted by participating partners. He said he hoped for a “viral effect” to bring in demand, and demonstrate to the partners that they should invest in HD.

Akamai competitor Limelight announced HD support last week. And Web video sites such as Stage6 and Vimeo are already trying to differentiate by offering higher quality streams, at substantial cost. In fact, DivX had to spin off Stage6 to decrease operating expenses. With that in mind — who doesn’t want to get rid of that post-YouTube blurriness headache? We definitely think higher-quality video (we’ll see about HD…) is going to do well.