Can Loyalty Exist with Innovation?

Fast Company just posted on its blog the following quote from an article written by Susan Lyne, the CEO of Martha Stewart Living Omnimedia: "If people get what they expect from a brand -- and more -- they're going to stick with it." 

This makes sense as it relates to fairly repeatable purchases or rarely-changed products.  But some professional service firms are wondering about the delicate balance between loyalty and innovation.  No two professional services are ever exactly the same, even those delivered by the same individual at the same firm; the client's needs are a continuously evolving target; and needless to say, professional service firms have yet to crack the code on formal innovation.  Lyne's very simple sounding remark succinctly articulates the challenge for professional service firms: growing their clients' loyalty, given a continuous flux of intangibles.   

Has any one heard about a professional firm that has successfully managed the juxtaposition of loyalty and innovation?