In any business it is critical to provide consistent service to your customer each and every time. You don’t know which aspect of the service or the combined nature of the service they like. However they know when it is absent or changed and may not return based on the changing experience.
I will use the example of a barber I once had to illustrate this principle. The first time I went to this barber I was very happy with the service I received. I sat in the chair and he combed out my hair prior to giving me hair cut. He then cut my hair and trimmed my beard. After giving me a line up with the clippers he followed that up by using a straight blade. He placed a hot towel on my beard and neck and applied after shave. He finished up my spraying sheen spray on my head. I was very pleased with combined service and returned 2 weeks later.
This time the barber didn’t comb my hair prior to giving me a hair cut and didn’t use the straight blade after giving me a line up with the clippers. I didn’t say anything about the change in service, my hair still looked good. I returned again 2 weeks later.
This time the barber combed my hair prior to giving me a hair cut. However the use of the straight blade, hot towel and sheen spray were all absent. I again didn’t say anything about the change in service, however I didn’t return in 2 weeks or at any point after that. Each time the barber cut my hair he did a decent job, but I didn’t like the constant change in service since my first visit.