Customer relationships. The ways in which the business connects with, relates to, and retains customers.

One unusual offering comes from eDataSource.com, which specializes in tracking competitors' e-mail marketing campaigns. The company regularly tracks 24 million daily e-mail campaigns from 50,000 brands and can provide fascinating intelligence about things your competitors are doing in your customers' e-mail inboxes.

Revenue streams. Where the money comes from: how the business generates income from the value propositions it offers to customers.

You need to know your market extremely well to run your business. What you do not have to do, however, is to include everything you know about it in your lean business plan.

Key partnerships. Outside organizations, such as suppliers and partners, that help the business model work.

the number one differentiator between an aspirant and a real founder is that the former is in love with his product, but the latter is in love with her business model.

There are many ways to think about a business model. One of the most effective is described and illustrated by Alexander Osterwalder and Yves Pigneur in their best-selling book Business Model Generation.* In their structure, a business model includes nine basic elements:

Number of potential purchasers × Percentage of capturable market share × Absolute dollar amount of each sale × Percentage margin of net profit = Total potential profit

The normal lean planning process is what Tim Berry calls the PRRR cycle—“plan, run, review, and revise.”