A sales technique or logical mistake whereby only the best case scenarios are shown and potential downsides omitted from the documentation or presentation. 

Sometimes this is unintentional, as the author of the idea may not know about or recognize the downsides yet. An extreme case is an acne medication of the 1950's that was later discovered to cause birth defects.
  
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See: SilentFailureNoisySuccess, FallaciousArgument