ISI Group analyst Ross Muken says investors should watch Walgreen's (WAG -1%) sales results...

|By:, SA News Editor

ISI Group analyst Ross Muken says investors should watch Walgreen's (WAG -1%) sales results closely over the next two months to gauge the willingness of customers to return back to the company's prescription services. While execs keeps pointing to the Walgreen loyalty program as a revenue driver, you have to get them in the door first to reap the benefits. (Earlier: Walgreen's September sales disappoint)