Ifferent strategies for protecting market share

Their are different strategies for protecting market share. What are a few of these strategies and how do they relate to some real-world brands? Please offer up a couple of brands and steps taken by their managers to protect their market share. Discuss in 250WORDS

DO NOT USE THE BELOW AURTHUR AS A REFERENCE. PLEASE USE A DIFFERENT SOURCE.
Kotler, P., & Keller, K. L. (2012). Marketing management (14th ed.). Upper Saddle River, NJ: Pearson Prentice Hall