AdDuplex, the Windows Phone cross promotion network that aims to help developers get exposure for their apps by exchanging ads, has now made the jump to Windows 8. Launching today in beta form, it is currently available for XAML-based Metro-style apps written in C# and Visual Basic, while support for HTML/JS and C++ based applications will be added later on. As a bonus, the exchange ratio will be upped from 0.8 to 0.9 during the beta phase, which means that for every 10 ads displayed in your app, you’ll get 9 instead of 8 impressions of your own ad.
Additionally, the first five Windows 8 apps to use AdDuplex will get a 250,000 impression bonus, which can be even used for advertising existing Windows Phone apps. Developers who want to sign up for the new service can do so at beta.adduplex.com (via AdDuplex blog).