There are thousands of small communities online that can benefit by adding a job board to the mix. Case in point, TruckerCountry. Run by a former truck driver, the site offers CDL practice tests and resources that help people become truck drivers. The site reaches 100k users each month so when the owner approached me about if he should add a job board my answer was a resounding YES!
Trucking jobs are hot and show no sign of slowing down as we head into an era of delivering everything we order online. Somebody has to get those goods to your doorstep and truckers are the main reason that happens.
So if you know anyone that has a niche blog or site like the above that has an existing community (and traffic) tell them to add a job board. It will increase page views and eventually add more revenue to their business.