If you expect to be the market leader in 2 years, you need to demonstrate why this is possible and how you`ll meet this goal. If you say your product will be viral, you have to support this statement with facts and a strong analysis explaining why people will like your product or service and how they`ll help you promote it.
Write your plan using language that your audience will understand. Accommodate your investors, and keep explanations of your product simple and direct, using terms that everyone can understand. You can always use the appendix of your plan to provide the full specs if needed.
The business plan is a necessary but not sufficient condition for finding outside investors. The plan describes the business and what it might become, and that`s all. A beautifully written, edited, and formatted business plan will not make a less investible business more investible.
Why? Because once you know the details of your business inside and out, you will be better prepared to write your executive summary. After all, this section is a summary of everything else you`re going to write about.
Likewise, your business plan should answer these questions during the short-term period, particularly one year; specifically, what your business`s goals are for the current year, and what is essential in order to make your first year a success.
Like anything else in business, a business plan should be judged good or bad not in a vacuum but in its business context with its specific business objective. Most of the online discussion about business plans is focused on business plans related to seeking investment, and I`m going to make the assumption in this answer that you are asking about those.