Warby Parker (glasses), Away (suitcases), Casper (mattresses) and Harry's (razors) are just a few of the feathers in David Bell's professional cap. The DTC (direct-to-consumer) guru and ex-Wharton School of business prof turned investor dropped by the OMR podcast to discuss his role in the DTC economy, why the business model’s success can be traced back to exactly three reasons and to what extent DTC brands now need local branches.