Does having a good Stack Exchange/Stack Overflow reputation improve your chances of employment?

I don't know the definite answer to this, but it seems that Stack Overflow's business model is at least partially edged towards this mechanism. SO members can sign-up for http://careers.stackoverflow.com, where employers can search for reputable software engineers and IT experts. I think one of the reasons employers turn to SO is because of the more informative profiles in their database. It is interesting to look at the cyclical effect of demand-supply: will high demand for c# people generate more questions and answers on that topic, because people are motivated to get a high ranking for that topic (means job opportunities)? I have never used SO as an employer (it costs a lot of money and I am not an employer), so I don't know how they rank the results, but I suppose that reputation can be used by employers to rank the outcomes. I  don't think the reputation system is sufficient in breadth to automatically match people with jobs, but my hunch is that it certainly counts.

I have a StackOverflow score over 200k but I don't think it really matters to employers. I've never been asked in an interview about my score on anything. They are much more interested in my skills and experience. That said, if you have a high score on StackOverflow, then you probably know some useful programming skills, you can write articulate answers, and you're engaged with your profession enough to help other people on your own time. That's what improves your chances of employment.

Certainly Yes, NOT because you have high reputation on StackOverflow but because of the experience you get in the process of earning those points.. I am very new to SO but just being there, helps you in many ways. For every question you will find someone answers in better way(may not be always) Use cases you see will be something which you would have never imagined! Problems you see will be well diversified which enables you to grow in particular skill set/programming language. Your skills will never get rusted. Example: Say, your current employer doesn't use C,C++ . Over a period of time, you will loose the touch of languages you learnt.. But SO helps you to keep in touch with those and grow better. I have seen answers of the users' with very few points and users' with thousands of points. You will be able to observe the maturity of the answer very clearly. Bottom line, its NOT THE POINTS, its an EXPERIENCE you earn matters. PS: If someone is getting points by just editing questions or so, will not help you in long run.

Current intern in the software engineering industry here. In my interview one of the questions asked in the first 5 minutes was "Are you on github or stackoverflow? What types of contributions do you have?" Being brand new to stack, quora and github not to mention the other opensource forums I'm getting involved in. I was completely honest and told them I had accounts set up and then they asked for them and asked specific questions about the things I follow. It helps because it shows that your active in the tech world and not just some guy who got a degree or is in school and only does programming in the classroom. The company I work for likes people who see code in their sleep and have algorithms in their blood. And there is no better way to show this than by being active in places like these.