This plugin shouldn't be on the WordPress repository. It should be featured on Envato or somewhere, and the authors should SEO their product to increase sales.
But you can't use the repository for promo-only purposes. There has to be a working plugin and from there, you can promote the premium/pro version.
Downloading the plugin from the repository alone does nothing; as I stated, there has to be a working plugin. And there is misleading advertising at that -- sign up for wpextreme and download the clearfix, and upgrade to the pro version if you like what you see.
Well, I signed up for wpextreme and there is no free clearfix there -- only the $15 version. It says on the website the free version is only for loyal customers who believed in you prior to this.
For these reasons, I feel this plugin should be promoted elsewhere on a marketpace, but not the WordPress repository.