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.
Basically, consumers are hunkering down to limit spending, save money, conserve resources, and change the way they've been living. The major influence on the health of an economy is the psychological state of its consumers. When there exists a broad belief that spending beyond necessity is unwise, people will change their habits and as a result, some businesses will have to close their doors. The economy is molting into a new, leaner animal. Rather than react in desperation to avoid doom, firms should interact with the current situation with innovative and forward thinking actions.
It may not be pleasant to imagine all the "what ifs," but doing it now and planning for those unexpected events will improve your company's chances of surviving a storm. For an excellent step_by_step guide on the details of developing a risk management plan, see the article "How to Develop a Risk Management Plan," by Charles Tremper at wikiHow.com.