It is often worth providing good financial incentives in the form of discounts to encourage this behavior. The metric that we use to track how well your sales force is doing in this area is Months up Front.
Getting paid more upfront usually also helps lower churn. This happens because the customer has made a greater commitment to your service, and is more likely to spend the time getting it up and running. You also have more time to overcome issues that might arise with the implementation in the early days. Calculating LTV and CAC
The Metric “Months up Front” has been used at both HubSpot and NetSuite in the past as a way to incent sales people to get more paid up front when a new customer is signed. However asking for more money up front may turn off certain customers, and result in fewer new customers, so be careful how you balance these two conflicting goals.