IDEA: How many new customers started ordering this month? More importantly, how many left?

Measure your number of active customers every month.  Who is falling off? How many did you gain? Are there any patterns in the losses or in the gains?  Are you attracting only small firms or only large firms in a single industry? Are your products or services limited to certain buyers?  Your sales people know your shortcomings and what you need to add to be more competitive. Why do they know?  They know what you are missing because it is causing them to lose bonuses and they want someone to do something to change that.  Do not just ask if you added or lost customers.  Ask why and make necessary changes.