If you want to sell your business idea to a potential investor (particularly in this age of over-the-internet angel investment), then you need to put a lot of time and energy into your business proposal.  After all, if you’re asking someone else to put money up to support you and your ideas, you need to make absolutely certain that both your ideas and your proposal are 100% up to scratch.

When it comes down to it, the key to writing a good business proposal - like the key to all writing - is to consider your audience.  So - what is the salient point about the audience for your business proposal?  What you need to remember is that the bank manager or potential investor reading your report needs to know, within a few seconds (or minutes at most) whether or not you and your idea are credible.  At heart, they won’t be assessing your idea - they can’t possibly have the same level of knowledge about the idea or the market as you - so they’ll instead be trying to work out as quickly as possible whether or not you know what you are talking about, and are good for your word.

This means that your business proposal - your representation of your business idea to a potential investor in written form - must be a scrupulously honest document, something that demonstrates in its integrity, clarity and precision that you know what you are talking about and are not concealing anything from them.  If you want to convince people, there is nothing more important than honesty.