If you have not already, setting up a capital committee to review expenditures in advance of the start of the project provides some assurance that the projects have been vetted against return on investment. Lastly, developing a post-audit process enables the team to review and monitor the progress of ongoing investments.
If an online business, you need to go into detail how you will attract customers to your website. General statements will contribute almost nothing to helping your cause unless you have detailed statistical analysis of tests you have conducted or of another similar business you have been associated with. If you do not have any data upon which you reference your estimates, it could show lack of proper thought to the remainder of your business plan.