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.
Competitive Analysis: Business by nature is competitive, and few businesses are completely new. If there are no competitors, be careful; there may be no market for your products. Expand your concept of competition. If you plan to open the first roller skating rink in town, your competition will include movie theaters, malls, bowling alleys, etc.
Location: Writing down the location of your business is very important. Locations with greater customer traffic usually cost more to buy or rent, but they require less spending for advertising to attract customers. This is especially true of retail businesses where traffic count and accessibility are critical.
When you sit down to compile all of the elements of your business plan, make sure you have each section able to stand on its own merits. This means you should not reference other sections sending the reader (your potential investor) back and forth between sections.