Do not try to write your business plan in one sitting. As I mentioned in the beginning, for a traditional brick and mortar business, it could take in excess of 100 hours to compile all of the information needed into a comprehensive but yet understandable document. For online businesses, probably not that long. But your final product should be well thought out, well documented and easily understandable.
No matter the economic slump, increasing profits is typically the number one goal of any business. To ensure profitability, a company must demonstrate a competitive advantage over others in its industry, either by cost leadership (same product as competitors, lower price), differentiation (same price, better services), or focusing on an exclusive segment of the market (niche). For long term maintenance of competitive advantage, a firm must ensure that its methods cannot be duplicated or imitated. This requires constant analysis and regular reinvention of competitive strategies.
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.
Make it enthusiastic, professional, complete, and concise. If you are applying for a loan, state clearly how much you need and be precise in how you are going to use it. Also include detail about how the money will make your business more profitable, thereby ensuring repayment of the loan.