When I worked for (a well known database company) one of the consultants told me the following story about a bank in the US:
They did some data mining and customer profiling to identify who was “expensive”, as in they complained a lot and had basic accounts that did’t make a lot of money, i.e. the cost more to serve than you were ever going to make from them.
As per the terms of service these customers were put into “special” accounts that reflected the real cost of serving them.
When they complained (surprise) they were given application forms for the bank’s main competitor!
The other bank did’t understand what was going in until most of these customers had left and they had to increase the size of their call centre to deal with the load.
Call me cynical, but maybe if you can’t make any money let people leave and make it your competitors’ problem?