"[...] latest App Store cheat: SEO-style keyword gaming in the app's description text. [...] Each contains this exact paragraph at the end:

Customers who purchased this game also liked: [Named App A], [Named App B], [Named App C], [Named App N], etc [neither connected to, nor produced by this app's advertiser, merely a list of top popular ones __Ianf]

[...] this flagrant keyword spam is phrased in a way to make it seem like the list of apps is generated by the App Store's recommendation engine."

http://daringfireball.net/linked/2008/12/18/app-store-seo-cheat