You should provide sufficient time for the investor / business owner to go through the details and then you can reach out to them again to understand their decision. A useful technique in such situations is the ‘call-mail-call’ tactic. Call a business owner / investor and brief them about your business / requirements. Wait for a few days, and then drop an email enquiring if there’re any updates from their end on the same. Fast forward a few days, and then call them again to remind them. This is a good method as it tells the business owner / investor that you’re genuinely interested in making a deal, and also gives them time to make a decision.
Inspite of the above if things don’t progress as per your expectations then it would simply mean that the buyer / seller is not interested at this point in time. You need to move on and start talking to other buyers / sellers. The deal gets consummated only when there is a meeting of the minds between both the members.