CVS Health's $69 billion acquisition of Aetna will change the pharmacy and health-care industries alike. The deal creates the first health-care triple threat, combining CVS's pharmacy and pharmacy benefit manager platform with Aetna's insurance business. The threat to pharmacies — or those that own them — is the way in which the two will leverage Aetna's network of 46 million members to drive traffic to CVS stores. Aetna subscribers will be able to pick up prescription medicine in CVS stores while receiving pharmacy and medical services. Eventually, they may also be able to find a lower co-pays only CVS. "Over the next couple of years, you'll see a dramatic change in terms of the store not just being about products but also service offerings that can help people on their path to better health," CVS CEO Larry Merlo told CNBC earlier Monday. Retailers are now facing an entirely new form of competitor, while contending with the potential threat of Amazon encroaching into their space. They have already begun to examine what the deal means for their business, and the solution may entail acquisitions, industry advisors say. The pool of retailers directly impacted is relatively small. They include Kroger, Wal-Mart and Walgreens Boots Alliance and — to a lesser extent — Rite Aid. Of the retailers, Walgreens arguably has the most to lose. It the most similar to CVS in business model and the most reliant on drug sales to drive traffic into stores. The household and personal care products it sells can now be found online and often for less. The retailer generated 69 percent of its U.S. sales in its pharmacy. Abroad, where the retail industry is less competitive, it generated 35 percent of its sales in its pharmacy. But Walgreens many years ago set itself down a road different than CVS. Rather than diving into healthcare, as CVS did, Walgreens doubled down on real estate and international expansion. It acquired British pharmacy giant Alliance Boots in 2014, opening it up into Europe. It attempted to acquire Rite Aid a year later, in a $17.5 billion deal that looked to bring with it 4,600 stores. Regulators, though, whittled the deal down to a purchase of 1,932 stores for