Ask HN: Windows alternative to the Mac app store?

I operate a micro ISV and sell Windows and Mac versions of the same software application. The Windows version can be purchased from my own website ( http://hartcw.com ) using paypal/fastspring, but the Mac version is also available on the Apple Mac app store.

Sales from the Mac app store make up the large majority, as its so easy for a mac user to browse and search for apps directly from their desktop. Especially now with Lion, because the Mac app store is installed on every machine sold! This makes me think I must be missing a large market of PC users, who just do not get exposed to such software catalogues and hence never see the app.

What are the alternatives for listing/marketing Windows applications?