Please keep in mind though that it is a well known technique to try to build loyalty by doing something that the customer doesn't expect that isn't in your best interest.
The problem is this doesn't always work and isn't applicable in all situations.
The customer that you sell a laptop to may or may not return. But the salesman selling oracle would get fired for pushing a competitors product under the guise of building loyalty.
The problem is that practices like this are specific to certain places and situations.
Lastly, if you are a local small dealer you simply can't afford to easily lose a sale with the hope that the loyalty is paid back for years to come. You generally have to make hay while the sun shines.