Sign up for the Amazon affiliates program, then link them to useless homeopathic products and crap like that - tell them explicitly that they are useless and watch the money from the referral links roll in despite of that. They can never resist the easy way out, no matter how often we tell them they are being idiots. To gain extra income link them to your own Amazon store where you sell the products at higher prices. If you want you can donate a portion of the profits to  http://www.jamieoliverfoodfoundation.org.uk or something like that.