The United MileagePlus Explorer card is a very handy tool for travelers to have. Crucially, the card charges no foreign transaction fees, so you can use this card all over Europe and never be charged for anything but your actual purchases. In addition, the card allows you to get a free checked bag on United flights, and you can get priority boarding on United flights with this card. But the real benefit of this card is all the United frequent flier miles you can get while using it. I signed up during a promotion, where if I spent $1,000 in the first three months, I got 30,000 free miles. I liked this deal, because I didn't have to inflate my spending at all to get the points. Also convenient is shopping through the Mileage Plus shopping portal. I can get points for shopping through the website, even if I don't use my United card, and if I do use the card, I get double points! Sometimes stores also have promotions that give you 2-5x the number of points for your purchases. My only complaint with this card is that I wish it was easier to acquire more points quickly. I was hoping to use my points on a flight to Paris this summer, but that might be out of reach. Still, overall I would definitely recommend this card to those who love to travel.