Sign up for the Chase United MileagePlus Explorer Card and earn up to 40,000 miles. Earn 25,000 bonus miles after your first use and 5,000 additional bonus miles for adding an authorized user within two months of opening your account. Plus, earn 10,000 bonus miles when you spend $25,000 or more on your card each calendar year. You also get your first bag checked for free, priority boarding and United Club passes. Plus, the $95 annual fee is waived for the 1st year.