Here's how Nokia describe the "Marketing in a Box" service:
We understand that for a developer, marketing an application effectively is a key to succeeding in the market. To help developers effectively market their apps, we have been actively working on a suite of marketing tools for your apps called “Marketing in a Box”. Today we are introducing Marketing in a Box beta. This suite of tools will help developers create winning app marketing strategies and the assets to support them.
Marketing Guidance
The marketing guidance takes the form of a series of videos (before the launch, during the launch, and after the launch), and a 46-page PDF document (A Shortcut Guide to Marketing Success). The guide included information on owned media preparation, in-app business models, bought and earned media, launch preparation, maintenance and analysis.
One section of the guide talks about the importance of getting a presence in app news and review websites, and engaging with influencers. All About Windows Phone is an example of one site that developers can contact to get word out about their app, but there are plenty of others too. We welcome all contact from developers, be it via email, Twitter, or even in person.
Digital Marketing Toolkit
The digital marketing toolkit builds on the success of Nokia's automatic banner generator, which is now one portion of the asset generation process. Developers can now also automatically generate a promotional YouTube video, complete with Nokia Lumia branding, create a mini-website, and generate the code for a Facebook app (tab for an existing page).
Here's an example of the promotion video that can be automatically generated by the service. In this case it is promoting the AAWP app.