Many surveys contain stunning logic lapses, indicating no QA / review processes or that they're written by some pretty junior heads.

For example, confirming that you have never owned a snowblower in your life and never intend to, then asking deep, probing questions about your snowblower likes and dislikes. (I had a long one recently asking me what brands I thought were appropriate sponsors for Euro 2016, what their connections with Euro 2016 made me think, how often I watched Euro 2016 matches, etc.... after I made clear I am not a football fan and did not even know what Euro 2016 was.)

Or forcing you to enter false data (selecting a multiple-choice option even when none is "correct") in order to continue.

These things aren't that hard to avoid, but many survey firms don't seem to try that hard. I shudder to think of the weighty business decisions made based on the junk data these broken surveys yield.