Well, by others I mean the structured data, which has columns/fields and rows/records. There are many statistical models to do the analytic for them. Does text analytic work in a different way, both in the analytic process and statistical models.
Often times in text analytics you are trying to extract information from the text so it fits into other structured ways of looking at it and many of the statistical models used in other places are applicable for text, once you get the proper feature selection and representation of the text in place. The book is, in many ways, a description of how to do these things.
As an aside, I often find it ironic that people call text "unstructured", since it's very highly structured. We just haven't been that great at getting computers to understand that structure.