I bought a transportation deal by MobilCabs in Boston from LivingSocial that was supposed to offer me a round-trip ride to the airport. When I went to book it, they gave me a hard time finding a date, even 7 weeks in advance of what I wanted. They were very slow to respond, even on the phone saying they would call me back or email, but they often didn't. Though I had a reservation confirmation, they never showed up. Fortunately we didn't miss our flight for our family vacation, but it ended up costing me a lot extra money and aggravation. I would never use their service again.