Thanks to Vermont Folk Troth
In consumer behaviour studies, the Blissful Ignorance Effect is when people who have good information about a product are not expected to be as happy with the product as people who have less information about it. This happens because the person who bought the product wants to feel like they have bought the right thing. However, if the person already knows how the product works they have a tougher time trying to justify the product to themselves if it has any problems.
This effect illustrates how consumer’s goals subsequently change after they have made their purchases. People crave for precise, detailed information in their decision-making stage. However, after making a choice, priorities shift as people want to be contented with their decision. In order to achieve this, information vagueness possibly increases content and acceptance of that decision by concealing the full picture and justifying the decision made.
In an experiment to test the blissful ignorance effect, two groups were created and told information about a product. The first group was told about the manufacturer’s claims and given research from an outside company, the second group was given minimal information about the product. At the end of the experiment the subjects were interviewed and the researcher found that the subjects in the second group had expected the product to perform better than the first group had.
Read more here: Blissful ignorance effect – Wikipedia