Talk about bittersweet. A British bakery owner saw her profits for the entire year erased by an unexpectedly popular Groupon deal. Rachel Brown put an offer on the discount site for 75 percent off of a dozen cupcakes—and then was unable to manage the influx when 8,500 customers signed up. Brown had to hire temporary workers through a staffing agency (at a cost of $19,500) and ended up losing a few dollars for every dozen cupcakes she sold. “Without doubt, it was my worst-ever business decision,” Brown told the BBC.