  Contacting customer service via chat is a common practice. Because employing
customer service agents is expensive, many companies are turning to NLP that
assists human agents by auto-generating responses that can be used directly or
with modifications. Large Language Models (LLMs) are a natural fit for this use
case; however, their efficacy must be balanced with the cost of training and
serving them. This paper assesses the practical cost and impact of LLMs for the
enterprise as a function of the usefulness of the responses that they generate.
We present a cost framework for evaluating an NLP model's utility for this use
case and apply it to a single brand as a case study in the context of an
existing agent assistance product. We compare three strategies for specializing
an LLM - prompt engineering, fine-tuning, and knowledge distillation - using
feedback from the brand's customer service agents. We find that the usability
of a model's responses can make up for a large difference in inference cost for
our case study brand, and we extrapolate our findings to the broader enterprise
space.
