I know exactly what you mean.
The other day I received an invitation from a (credible) market research company to complete a ten minute online survey about pricing and revenue management in the airline business in return for GBP 50.
I said OK and spent five minutes clicking through 'pre-qualification' questions only to fail to proceed to the survey proper on the grounds that I was a consultant and not actually employed by an airline, which the market research company should have known because I told them about it when we last spoke, and therefore received nothing.
