Are there certain businesses for which it is impossible to write a business plan for?

[McSenior Junior]

I thought about it and film companies and social networking sites must be impossible to write business plans for, you can't do market research for a movie company and it is impossible to estimate the consumer consumption of these goods and services.

[Beardo]

You should be able to write a business plan for any business.

Compare other similar businesses; extrapolate.

[Darlene B]

While the business plan you write for certain companies may not look like everyone else's business plan, you should most definitely be able to write a business plan for ANY business. A business plan is simply that... a plan as to how you will operate your business. Who will do what. How you'll make money. How you'll advertise. What expenses you expect. And so on. You must be able to plan for any business and the "business plan" is just a written, and somewhat formal, projection of that plan.

[imisidro]

The companies you mentioned -- film companies and social networking sites -- actually have detailed financial plans. Why? Because they all have investors, and investors first look at the business plan

They estimate the financial data, benchmarking it with other industries. They do a lot of projections, making sure that it covers all variables and realistic or believable enough not to raise the eyebrows of the knowledgeable investors. Some even conduct surveys to have solid data backing them up

If you want investors, you'll come up with a business plan -- whether it is easy or very hard to do