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.
Second, your business plan should be a tool you use to run and grow your business. Something you continue to use and refine over time. An excessively long business plan is a huge hassle to revise—you`re almost guaranteed that your plan will be relegated to a desk drawer, never to be seen again.
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.
In the beginning, one may have the urge to delve straight into specific strategies, such as evaluating production methods, studying market segments, and evaluating the competition—but do not do that, at least not yet.
This can be as simple as having a mentor or partner review elements of your plan, or conducting market research and speaking directly to your potential customer base.
This means having the right financial statements, forecasts, and a digestible explanation of your business model available for potential investors. Writing your business plan helps you put all of those pieces together and create connections between them to tell a cohesive story about your business.