Now explain how regardless of your sample method, it's still not a science.
I’m pretty sure that you just did, no?
I hope you didn’t get the mistaken impression that I am coming out in favour of (or even expressed an opinion regarding the validity of)survey methods. Gusto asked a fairly elementary question, and I used pictures to explain the methods used by “professionals” in his industry.
Do not take my statement as an endorsement. It was not meant to be.