The service, named the SeeSaw Ad Selector, enables visitors to the website to select from three different video ads to stream before their chosen on-demand programme.
Ad Selector, created by SeeSaw in partnership with technology firm Brainient, is designed to allow brands to target viewers with tailored advertising.
Already launched in the US, the technology "stimulates" viewers' engagement with advertising and improves their brand recall and desire to make a purchase.
The Ad Selector is in operation now across a range of advertising-funded shows on SeeSaw.com, combining traditional video formats with flash-based overlays.
"We're excited to launch the Ad Selector format - a win-win for the advertiser and the user," said Ben Williams, head of advertising for SeeSaw.
"The Ad Selector is simple and effective, essentially giving the user the choice to pick the advert they wish to see. This puts the user in control of the advertising experience and therefore increases their engagement and purchase intent.
"Our vision is to create a unique environment for advertisers to reach their audience through innovative methods, and today's announcement is the first step towards this, with more initiatives in the pipeline."
Brainient chief executive Emi Gal added: "Brainient is proud to be the first interactive video company in Europe launching an interactive video Ad Selector. We're very excited about our partnership with SeeSaw.com and look forward to helping advertisers engage their viewers by making video ads interactive and social."
Ad Selector builds on SeeSaw's commercial launch in February, which saw its first three months of advertising inventory completely sell out, including ads from brands such as Coca-Cola, Heinz, Ikea, O2 and Sainsbury's.