This spreadsheet provides two models for calculating the cost of sale for a revenue channel of a business.

The first model calculates costs through Contriubtion Margin.  It starts with an estimate of the lifetime value of a customer.  Next, Cost of Goods Sold and Marketing Acquisition Cost are subtracted out.  Then, the Sales Cost and Account Management costs are subtracted out.  Each of these cells reference other tabs itemizing costs such as salary, commission, benefits, software licenses, office space cost, etc. 

The sales cost is estimated by taking all of these costs and multiplying them across the number of sales people, then dividing it by the number of deals they close in a given month. This provides the cost per deal.

The account management cost (or client services cost) is calculated by taking the similar costs and breaking it down to an hourly rate for the account manager.  This is multiplied by the number of hours the account manager spends on a given account throughout the average life of an account to provide a cost per account.

The net of this model provides amount that is contributed back to the business (contribution margin) from this particular revenue channel.

The other model provides net margin per deal.  It also starts with the average lifetime value of the account and subtracts out COGS and marketing acquisition cost.  Then, instead of subtracting itemized sales and account management costs, it subtracts out the company Operating Expense (OpEx), as a percent of revenue.  Using this model, it is subtracting out operating costs associated with the entire company instead of just the revenue channel generating the revenue. The result is net profit per new account signed expressed in both dollars and as a percent of revenue.