a) The customer wants “proof” of something which is contrary to commonly held belief - anything from “proof that the holocaust didn’t happen” to “proof that prune juice cures scrofula”.

b) The answer to the question is “No” or its equivalent e.g.

Q. “What are five interesting things for a tourist to do in Little Wagga Wagga West”
A. There aren’t any.

c) The customer wants suggestions for their party, holiday, wedding, mother-in-law’s birthday present, etc. The risk (from experience) is too great that not only will the customer not like any of my suggestions BUT ALSO be rude about it. As in “Don’t be ridiculous, you must know my mother-in-law hates pecan pie / diamond necklaces. “

a. The asker is too specific: for example, asks for the professions with highest and lowest job satisfaction, which we might not be able to deliver. The asker might be just as happy with pointers to a variety of articles highlighting professions that tend to have high or low job satisfaction - but researchers don’t know that this would be sufficient.

b. The question is partially-answered in the comments or in the clarifications, and researchers are reluctant to jump in with a fuller answer.

c. The customer doesn’t respond to a request for clarification (or doesn’t respond usefully).

d. The researcher is afraid of getting less than a five-star rating, so will not post a good and useful (but not ultimately perfect) answer.

a. Asker wants too many parameters answered - No matter what the price this is a very tough questoion since all the hard work you put into hours of research will go down the drain if one factor cannot be completed.

b. Questions that go against my moral or ethical beliefs - Just as I wouldn’t take projects that I feel are contrary to my moral beliefs, this is also how I treat Google Answers.