Answer:
providing too vague and few details
Explanation:
The first thing that should come to the mind of someone trying to sell an idea or make people understand it would be to as clear as possible about what you're saying and what you want to achieve.
When a writer or speaker provides details that are too vague and not clear enough to understand their purpose or provide few details that are not able to explain clearly what the idea is about, then it would be very easy to dismiss such idea.
