Imagine checking into your hotel room to find a beautiful pot of your favorite green tea, with a note from the general manager. It’s perfectly tailored for you: Your afternoon ritual is to take a break with tea, and you are delighted to find it waiting for you in your room.

At a meeting I recently attended, a travel company explained they were rolling out a loyalty program that asked customers for a wide array of their preferences, right down to the magazines they liked and type of wine. The plan was to surprise and delight—those traditional service goals. They would, from time to time, surprise their most valued customers with the magazine or wine or any of the other lifestyle preferences they had specified.

Technology and big data allow travel companies to personalize customer experience in ways never before possible. But that comes with risks.

The industry professionals who were at the meeting all agreed: “Great idea! That would be cool!” Yet every positive comment was followed by, “But you’d better be able to deliver.” Because the opposite of “surprise and delight” is “disappoint and alienate.” If customers come to expect a personal touch and if it’s not there or (even worse!) it’s In Style instead of Sports Illustrated, you’ve just blown it big time.

Expectations of personalization have risen dramatically. It’s what we all want as customers: to be recognized, to be treated as special and to get just what we want. As this tailored experience becomes more and more possible—even common—our expectations are so high that when they’re not met, our opinion of the company can drop even farther.

As a traveler, I am probably more forgiving than most. I know it’s almost impossible for airlines and hotels to get it right every single time. At the same time, I do notice that I have raised the bar higher than ever. Truth is, I like green tea and not black, and I will be more disappointed with black tea than none all. Be careful out there. Good intentions can only carry a loyalty program so far.