simonmc - 10:11 am on Dec 19, 2012 (gmt 0)
I think this is a dangerous game to play if you want to keep your link directory.
Imagine that all these people who have asked for their link to be removed from your directly, file a disavow file with google about your site links. Soon google is going to see a pattern about your site and rather than you making 20 bucks a throw or whatever you manage to extort, google is going to wipe you from the planet.
Rightly or wrongly, Google has no hard and fast rules about anything. So one practice you engage in is just as likely as any other to fall foul of the mighty G.