CVS is following other retailers, including Target and Walmart, in introducing an in-house digital ad network. The CVS Media Exchange platform (AKA cMx) is intended to enable the drugstore chain’s consumer packaged brand suppliers to “efficiently reach existing and potential customers” via in-store ads, website banners, online video, social media and search engines. Norman de Greve, CVS Health’s CMO, said the data the retailer has on 74 million consumers will be invaluable to advertisers.