What Wall Street shenanigans are giving investors fits this week? Dayana Yochim and Alison Southwick rip into Groupon (Nasdaq: GRPN) and its ongoing struggles with basic math, Best Buy's (NYSE: BBY) turnaround-plan blunders, and the mother of all marketing misunderstandings, courtesy of Kraft (NYSE: KFT).

Alison Southwick and Dayana Yochim own no shares of the companies mentioned. They do, however, read every single word of every single newsletter service that The Motley Fool publishes. You can, too, for free and for 30 days! The Motley Fool owns shares of Best Buy and Wal-Mart Stores. Motley Fool newsletter services have recommended buying shares of Wal-Mart Stores and creating a diagonal call position in Wal-Mart Stores. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.