Switching banks after a merger. Banks that merge with others to form ‘mega-banks' sometimes leave customers dissatisfied with impersonal service. A poll by the Gallup Organization found 20% of retail customers switched banks after their banks merged with another (Bank Marketing, Feb. 2009). One year after the acquisition of First Fidelity by First Union, a random sample of 25 retail customers who had banked with First Fidelity were questioned. Let x be the number of those customers who switched their business from First Union to a different bank.