[refrigerator]

Rest assured, people are using this stuff. It's not as sexy as deep learning, but for small/medium data problems where the domain is reasonably well-understood and experts have useful priors (read: the overwhelming majority of business problems), this is pretty much the only unified framework for learning from data while incorporating uncertainty.

Here's a product that claims to be solving lots of problems for lots of people using Bayes nets:

https://www.agenarisk.com/customers

[vidarh]

Almost every home-grown search function in existence could benefit from it, in my opinion. Everywhere where you have a useful feedback that imply good relevance (e.g. clickthroughs, customer actions), but do just straight textual keyword searches, a Bayesian approach can do better. Often there are more complex methods that can do even better, but the beauty of using a Bayesian approach is that it's so simple. I've seen so many cases where people spend tons of effort manually tuning product searches etc. when they can trivially have the engine automatically tune itself to what actually produces the best business outcomes.