Your Online Choices website says "On this website you'll find information about how behavioural advertising works, further information about cookies and the steps you can take to protect your privacy on the internet."
Also gives you easy tick box optouts from companies OTHER THAN those you've visited who place cookies to assess your advert 'needs'
It got rid of my persistent 'we will buy your car' and 'Travelodge' ads.

Website is www.youronlinechoices.com

(I couldn't get the clickymaker to work tonight. Kept adding mudcat to the url and so turning up 404 not found)