If they invest money in the early stage of your business, this is a great opportunity to put a "market" value on your business. One of the hardest thing for any startup who only have a protype with no revenue is put a value on your business. For eg. One of the company I raised early funding for, we secured 2 lots of $150k for 10% each. So that equates a market valuation of $1.2m. Your accountant can help you set this up and create a CAP table to keep track of equity dilution.