If a new CRM system is deemed good for the company, the commission model should provide compensation if a deal is correctly entered into the new system, and reduced commission (or no commission) if the systems and processes are not used. If you want to get even more rigorous, you could track the time required for back office processing of a sale and deduct compensation for difficult-to-process, and hence, more costly deals.
Despite all the dire predictions on sales' acceptance of a new system or process change, like any other employee most salespeople want to be high performers, and if they do not, they should be shown the door.
Patrick Gray is the founder and President of Prevoyance Group, located in Harrison, NY. Prevoyance Group provides strategic IT consulting services. Past clients include Gillette, Pitney Bowes, OfficeMax and several other Fortune 500 and 1000 companies. Patrick can be reached at firstname.lastname@example.org.