In the Ubuntu Software Center, how are apps promoted?

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http://askubuntu.com – I have made a Kakuro game called Sukaro for Ubuntu 11.10 and its successfully published in the Software Center (Its a commercial app). And so far, I have not seen any advertisements (on websites, etc) regarding Ubuntu applications. So I was wondering, if you want to promote your published app, what should you do? (Aside from the most obvious things like Tweeting, etc.) What options does a software developer for Ubuntu has for promoting his/her applications? Are there any specific review sites or such? (HowTos)