Know Your Twitter Followers with Machine Learning

From their on documentation on the "Keyword Extractor" module:

This keyword extraction algorithm employs statistical algorithms and natural language processing technology to analyze your content and identify the relevant keywords.

The source code doesn't seem to be available, but presumably by "statistical algorithms and NLP" they mean TF-IDF.

Question is -- is this what they mean by "machine learning"?

And more to their point -- do their investors know what's going on here?