The human mind is inquisitive. It is always looking for meanings and answers - much of the time it is doing this without us being consciously aware of it. Where we cannot clearly see a reason for an event or events, our minds tell us that something is difficult. We all have examples of something that we are good at now that at one point would have seemed impossible to us.
At other times we can percieve something that we don't understand as boring or fussy, or we can even assume these things of the people who are presenting them. How likely would you be to buy from or work with somebody that you thought that about?
The trick in business is to keep everything as simple as possible. If people, and in particular, customers, perceive something to be complicated they will find it difficult to want to engage with you and that will of course hurt your profits.
A common mistake is to assume that the people you are talking to know about your product or service. This is especially true of IT consultants! If you are in any doubt about the depth of a customer's knowledge, ask questions. Find out what people know and want, and fulfill their needs starting from their perspective.
Think also about the media you are using to get your information across. I use teleseminars to get across ideas that take a bit more thought. People find it more difficult to read than to hear so I let them hear it. I worked with a telecoms company with a great product but who were struggling to get their message across on their website. The answer was to do a short cartoon. Instantly people could understand their proposition. You can see it here.
Keep things as brief, interesting and simple as possible at all times. You can always have the detail on hand somewhere else.