Good point Griffygriff... perhaps the survey companies are on to those that take surveys over and over, not to provide valuable information to the survey companies, but to pad their WGT accounts.
I can't be sure of this... could be wrong... but guessing that most of the survey complainers try to take those puppies on a terifically repetitive basis. If I'm the survey company I don't want those opinions ad infinitum... they don't effectively add to the marketing data base.
WGT shoud put a limit on surveys... i.e. one per person per category.