What are the requirements for a new ad unit in AdDuplex?

You have to choose your ad unit's target type by which you are saying what app you are going to promote with generated impressions: the app with AdDuplex implemented or another store app. You also need to select how you will be promoting your app, using text or text and image ads. 4 text ad lines are necessary while image ad is optional. See text ad copy and image ad copy requirements before you submit a new ad unit.