A while ago, Ian Walker started a series of posts aimed to help you build a marketing strategy for your WP7 apps. It's a good read, so don't miss it.
Source: Ian's Blog
This is an on-going list of links relevant to independent developers looking at marketing their own Apps. (I’m seeking useful feedback and criticism on all these short posts please. The end result will form a part of Mike Ormond’s’ forthcoming WP7 Kindle Book).