It is offering exclusive access to 20 advertisers for the first three months of the launch. One agency source said that advertisers were being asked to pay $100,000 for the initial trial.
Advertisers said to be in advanced talks with Joost include Unilever, Philips and Intel. Sources said the advertising model on offer is "fairly traditional" and involves the equivalent of traditional TV spots around programming.
Joost was thought to have been in talks with one media holding company about exclusive access for its clients, but this deal was not concluded.
Separately, Drum PHD has signed a deal with Joost to have a channel on the website devoted to its ad-funded programming for clients.
Hype around Joost has been building since it was announced last year that the Skype founders, Niklas Zennstrom and Janus Friis, were working on the project. It is currently at beta test stage, and claims to offer "the best of TV and the best of the internet" and will be available to viewers for free.