We have developed a free responsive WordPress theme called Franz Josef, with paid premium addons that can be purchased by the theme's users. The premium addons add substantial feature addition to the theme.
Currently we are getting about 100 new downloads per day on average with about 0.1% conversion rate to the premium addons. The short term goal would simply be to increase the downloads per day rate to at least 500 downloads per day within a period of 3 months.
We do have Twitter and Facebook accounts and pages, but these are rarely active as we have very little manpower resources. We are flexible in the marketing strategy that you might employ, as long as we can be reasonably confident that they will work. We are not averse to paid strategies, but you must convince us that their ROI is worth it.
Links for your further consideration:
Franz Josef theme: [url removed, login to view]
Premium addons: [url removed, login to view]
Live demo: [url removed, login to view]
Twitter page: [url removed, login to view]
Facebook page: [url removed, login to view]