Daniel Kahneman won the Nobel prize for Economics in 2002, despite never taking an Economics class. 

In this video he talks about his work and particularly the difference between what he calls "The Experiencing Self" and "Remembering Self". The Experiencing self is in the here and now - it experiences a holiday in realtime. The Remembering Self is the memory of that same holiday. And it is a very fleeting snapshot of the holiday at best. 

The key point is that, from a client management point of view, "the remembering self is the one that makes decisions". Decisions are taken based on our memory. 

"We don't choose between experiences, we choose between the memories of experiences." - and those memories are formed by two particular events.  Peak Experiences, the extreme moments, and Endings: "Endings are very important".

So, when dealing with your clients, remember that being good most of the time isn't enough. You must must manage those Peak and Ending experiences.

With the Peaks Experiences: Make sure there is one excellent event, one stand-out moment. And make sure, that when things go wrong that you talk to your clients so that the experience can not fester and become a bad Peak experience!

And at the End, before renewing hopefully, make sure you deliver with real quality, save the best 'til last. But equally, if it really is the end, ensure that you off-board your clients nicely and with competence. So they remember you for your good sense and professionalism. And they'll be back.