An incentive is that little thing that can help encourage a decision to make a purchase.
We see factory incentives for car purchases all the time. It's a kickback from the manufacturer to help the dealership sell more cars.
Are you worried about the cost of an incentive to try your restaurant? Work with your suppliers to help offset the cost of an item. Mentioning a brand name within the incentive may be worth the supplier giving you free products.
Just one thing, don't use an item as an incentive because you get the product for free. Make sure it fits within your brand.
Having a successful restaurant is always about creating relationships with your guests and your suppliers.