Going to the bank requests human interaction. In China employees face their desk, their computer, their bureaucratic actions, rather than the costumer. The chair in front of the window is either too far away, too high or too low to be comfortable. There is a kind of top down intimidating interaction.
Yin Yi 银亿 literally means 'Silver Hundred Million'.
In ancient China silver 'blocks/units' were used for financial transactions. The word for 'bank' in Chinese today is Yinhang 银行' which means 'row of silver'. 'Yin 银' is thus associated with 'money' and 'financial transactions'.
'Yi 亿' is symbolic. The largest number in Chinese is 10.000 or 万. It symbolizes 'a lot', 'endless'. 'Long Live the People's Republic of China' sounds in Chinese like 'ten thousand times ten thousand years for the People's Republic of China' 中华人民共和国万万岁. The character Yi 亿 means 'ten thousand times ten thousand 万万' and is used symbolically only.