Projected Financial Statements: These statements are usually helpful, but not necessary. You will develop and describe your strategies for the business throughout your Business Plan. In the financial section, you will need to estimate the financial impact of those strategies by developing projected Income Statements, Balance Sheets, and Cash Flow Statements.
It is usually recommended that these projected statements be on a monthly basis for at least the first twelve months or until the business is projected to be profitable and stable. Activity displayed beyond the monthly detail may be in summary form (such as quarterly or annually). The forecast period for most business plans is two to four years.
If an online business, you need to go into detail how you will attract customers to your website. General statements like "I will use Face Book ads and email marketing" 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.
So, although a detailed business plan may not be required for an online business, I am going to include it here so you can at least look at and consider each section and determine yourself if it applies to your business.