It's very much do as I do, not as I say. You'd be amazed at the nifty sales ideas your staff will come up with if you communicate that you will make a hero out of anyone who can advance the cause. It's also useful if you use your best sales staff to train your weakest performers. If you go about motivating this way some interesting psychology kicks into play. The beauty of working on your staffs' sales performance is that the extra money you bring in doesn't have the normal labour cost attached to it.
Additional sales are generally much more profitable than normal sales.
If you're looking for a quick boost to your bottom line, I'd recommend this as one of the fastest things you can do other than sacking your Chef or locking your spirits cupboard after work.