Account Revenue Forecast - can we set up a quota?

This business has a steady/repeat customer base and the CEO currently forecasts by assigning a particular $ sales figure to each of those customers for each quarter.  There is no opportunity per se ... just an expectation that each customer is likely to bring in that $ value of business.  Is there any way I can assign a quota to a customer in the same way I can apply a quota to a salesperson?  Any other thoughts as to how to handle this?  I thought of creating a "dummy" opportunity for each customer for the quota amount and forecasting that