On this week's episode of Slate Money, host Felix Salmon of Fusion, Cathy O'Neil of mathbabe.org and Jordan Weissmann of Slate discuss Greece's showdown with its European lenders; competition inside the world of online travel, and the new film adaptation of "Fifty Shades of Grey," which begs the question: Are billionaires sexy? This week’s episode was sponsored by Stamps.com. If you go to stamps.com, click on the microphone at the top of the home page and enter SLATEMONEY for a $110 bonus offer, including up to $55 in free postage and a no-risk trial. And Citrix GoToMeeting, the easy way to meet with coworkers online. Visit GoToMeeting.com and click the “TRY IT FREE” button. Love Slate podcasts? Listen longer with Slate Plus! Members get bonus segments, ad-free versions, exclusive podcasts and more. Start your 2-week free trial at slate.com/podcastplus  

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