At best, according to Moodys, WAG gets back 85% of lost customers
Moodys actually said this:
"The new pharmacy network agreement is a credit positive event as it provides Walgreen with the opportunity to win back the 85% of the prescriptions covered by the Express Scripts contract that went to other pharmacies after the contract expired."
85% is just the beginning. Walgreens has studied all the loyalty programs on the market, both in and out of this industry, and has taken the best features of all of them and rolled it into THE GOLD STANDARD of Loyalty Programs.