Ask HN: What market demands can I solve with machine learning?

so while I'm learning machine learning I want to pursue some problems that are in demand by the market.

One example I can think of is a sentiment analysis on social media to measure some degree of product satisfaction. However, at one point can you confidently state that you've found the appropriate product satisfaction? What if there were errors along the way (NLP not working properly or false positives)? How would you consolidate such things to a client? Social media related machine learning seems dime a dozen anyhow.

I guess I am trying to employ the same philosophy to when I was learning how to program. Create something that is in demand by the market to best learn the trade. I want to do the same thing for machine learning, computer vision, but am not able to visualize what potential problems that are in demand by the market are worth pursuing.

So, what immediate problems do businesses or industries face that I can solve with machine learning?