Generally, I refuse to answer surveys conducted by phone. As a result of this, on one occasion I didn't participate in one of the well-known opinion polls regarding voting intentions. Only later did I think about the name of the organisation that had been mentioned (but which I had not absorbed at the time) and realise that this could have been my opportunity to influence things.
However, when the opening sentence includes the word "public transport", I can't resist! A particular group has been retained by the Department of Transport, who it seems are commissioned to undertake surveys from time to time on various aspects of the system. So when I receive a phone call with the opening words "This is the Wallis Group and we're surveying user attitudes to [a particular aspect] of Melbourne's public transport", I sit back and I offer my views! Once I even wrote a follow-up letter to clarify one of my answers, and received a satisfactorily reply.
The only issue is that I've participated in 3 such surveys over the past couple of years! I suspect that I've made it to a data-base of responsive people. Perhaps writing a letter may not have been the best move had I wished not to be bothered. I don't suppose there's anything wrong with this, so long as the Department is aware that the results it receives may be from some sort of consultative panel, not users chosen at random!