We recognize revenue based on the consideration specified in the contract with the customer, excluding any sales incentives (such as loyalty programs and customer rebates) and amounts collected on behalf of third parties (such as sales and excise taxes). The majority of our revenue is generated at the point of sale in our retail locations. Revenues consist of fuel revenues, nonfuel revenues and rent and royalties from franchisees. Fuel Revenues. We recognize fuel revenues and the related costs at the time of sale to customers at our company operated locations. We sell diesel fuel and gasoline to our customers at prices that we establish daily or are indexed to market prices and reset daily. We sell diesel fuel under pricing arrangements with certain customers. For the year ended December 31, 2018 , approximately 80.6% of our diesel fuel volume was sold at discounts to posted prices under pricing arrangements with our customers, some of which include rebates payable to the customer after the end of the period. Nonfuel Revenues. We recognize nonfuel revenues and the related costs at the time of sale to customers. We sell a variety of nonfuel products and services at stated retail prices in our travel centers and standalone restaurants, as well as through our RoadSquad, RoadSquad OnSite and TA Commercial Tire Network programs. Truck repair and maintenance goods or services may be sold at discounted prices under pricing arrangements with certain customers, some of which include rebates payable to the customer after the end of the period. Rent and Royalties from Franchisees. We recognize franchise royalties and advertising fees from franchisees as revenue monthly based on the franchisees' sales data reported to us. Royalty revenues are contractual as a percentage of the franchisees' revenues and advertising fees are contractual as either a percentage of the franchisees' revenues or as a fixed amount. When we enter into a new franchise agreement or a renewal term with an existing franchisee, the franchisee is required to pay an initial or renewal franchise fee. Initial and renewal franchise fees are recognized as revenue on a straight line basis over the term of the respective franchise agreements. For those travel centers that we lease to a franchisee, we recognize rent revenue on a straight line basis based on the current contractual rent amount. These leases generally specify rent increases each year based on inflation rates for the respective periods or capital improvements we make at the travel centers. Because the rent increases related to these factors are contingent upon future events, we recognize the related rent revenue after such events have occurred. Other. Sales incentives and other promotional activities that we recognize as a reduction to revenue include, but are not limited to, the following:  Customer Loyalty Programs. We offer travel center trucking customers and casual restaurant diners the option to participate in our loyalty programs. Our loyalty programs provide customers with the right to earn loyalty awards on qualifying purchases that can be used for discounts on future purchases of goods or services. We apply a relative standalone selling price approach to our outstanding loyalty awards whereby a portion of each sale attributable to the loyalty awards earned is deferred and will be recognized as revenue in the category in which the loyalty awards are redeemed upon the redemption or expiration of the loyalty awards. Significant judgment is required to determine the standalone selling price for loyalty awards. Assumptions used in determining the standalone selling price include the historic redemption rate and the use of a weighted average selling price for fuel to calculate the revenue attributable to the loyalty awards.  Customer Discounts and Rebates. We enter into agreements with certain customers in which we agree to provide discounts on fuel and/or truck service purchases, some of which are structured as rebates payable to the customer after the end of the period. We recognize the cost of discounts against, and in the same period as, the revenue that generated the discounts earned.  Gift Cards. We sell branded gift cards. Sales proceeds are recognized as a contract liability; the liability is reduced and revenue is recognized when the gift card subsequently is redeemed for goods or services. Unredeemed gift card balances are recognized as revenue when the possibility of redemption becomes remote.