It is now running for about 24 hours on my Wordpress website and I gained already 50+ likes (it is not a very popular website yet). If it's set up properly it works like a charm. Great benefit is the asset of showing the pop-up ONLY to people who are logged in to Facebook because that way you avoid the pop-up dialog "Sign in to Facebook to like this page". To avoid the banhammer I would recommend not to use more than 1000 likes a day, no matter how many visitors your website has per day.
Twists that can be used with this method: set up ANOTHER facebook fan page URL than the one your website is linked to so you can build a small empire of fanpages that can be exploited. DO NOT SPAM your fanpages (like 1 post every hour etc) because that way it will be flagged quickly.
SUPA DUPA TIP FOR GODLYLT
Let pop-up only appear for visitors coming from USA/UK (or other specific country) and who are logged in to Facebook.

:nana: