I always go to the end until I get the thank you page. Most of those you have to do at least a couple of pages I have had better luck getting them to credit though going all the way to the end.
I agree. I always click until I get to the end just to try and increase my chances of getting credit. These are the types of things I don't do more than one or two of in a day as they usually have tracking cookies associated with them or they track by ip address so I spread them out so I have a greater chance of getting credit for them.