The IBM computer that beat two former champions at Jeopardy is going to work for financial giant Citigroup. It follows on from existing contracts with healthcare firms.

While it may have seemed like a gimmick, there were very good reasons to develop the machine and test it on the TV game show. The “get answer, give question” format is particularly difficult for automated systems as not only must they decipher the clues from the answer, but there’s not always a single solution, meaning the computer had to process multiple possible responses and work out which was the most likely to match that chosen by the game’s question-setters.

In the challenge, Watson destroyed two human opponents by a three-to-one margin. That was despite the humans exploiting a tactical advantage in that they could buzz in and still have a few seconds’ thinking time before they had to provide an answer.

Since the show, Watson has already been licensed to health-care groups for data analysis where it’s shown the unusual ability (in computing) to process natural language and to deal with unstructured data sets. While it’s not been used in this way yet, there has been talk that it could perform well in tasks such as diagnosing an illness or condition working only from a list of symptoms, or carrying out similar work with computer tech support.

The Citigroup job won’t be quite as simple as picking stocks or other investments: the system is designed more for working with a set of data rather than performing “live” analysis. However, Watson will be used for financial research that brings together information from a wide range of sources including both objective data and subjective “sentiment” such as online comments. It should be able to hunt down particular concepts expressed in different ways rather than being restricted to looking for specific keywords.

Watson may also be used for verifying internal documents to help banks avoid unintentionally breaching regulatory compliance. Whether it will be smart enough to announce “Hey, if some of these folks default on their mortgage, it’s probably going to be for specific reasons that mean a whole bunch of them default at the same time and then we’re all screwed” remains to be seen.

It appears some of the fee for Watson’s services may be performance-related. IBM isn’t giving precise details but says that by 2015 the annual revenue from Watson will be at least a billion dollars.