In my experience, the best and really only way to motivate sales people to sell is through their wallets. I’ve seen lack-of-performance punishments of all various shapes and sizes shrugged off as quickly as they were handed out, but the second a deduction in pay is discussed – for a sales rep – the earth stops.
Commission: On a micro level, the rep needs to receive a commission tied to each and every sale. Whether that be a percentage of the margin of each deal, a percentage of the total price of goods sold, a set dollar amount attached to each sale – whatever it is, the sales rep needs to experience an addition to their bank accounts as a direct result of every sale.
Bonuses: On more of a macro level, the rep needs to have bonuses kick in when wider-encompassing sales goals are met. For example, a rep should have a monthly, a quarterly, and a yearly quota that triggers a bonus when each quota is hit, in addition to a commission on each sale. What this alleviates is complacency. If a company establishes a monthly quota and only a monthly quota, there’s nothing to stop a rep from getting comfortable once that monthly quota is hit.
Team-Building Rewards: Lastly, a sales team should have goals that must be met by their entire team (ie. every rep of a specific branch reaches 100% of quota that month, the branch reaches 100% of its quarterly goal, etc.) and when this goal is met, the entire team gets to, say, take a group or team travel week. This is the kind of sales incentive that can really drive healthy competition and results.
The issue at hand is self-discipline and the ability to self-motivate. Very few reps can lay claim to either characteristic, let alone both. Because of this, in my opinion, bribery through their wallets is the best way to get sales people to sell.