Eneric Strategies model in sucessful Management

Using the Generic Strategies model, complete the following requirements:

Identify and describe 3 retail firms.
Note which of the 3 broad strategies that each firm seems to have chosen (low-cost producer, niche supplier, or differentiation strategy).
Identify at least 2 specific tactics that each of the three employ to support your opinion of their method of competing.
Do the tactics you cited seem to be working? On what evidence can you base your answer?