We would recommend both in a way a paid course can lead to more information on a particular subject,
but a free course can be effective, depending on which company is selling free or paid courses.
Conclusion: yes short courses do lead to jobs just not high up in the chain,
like an engineer, or doctor, or anything that is high pay work, but it can help with smaller jobs and pay,
but short courses are mostly something to learn that is a new skill that you might never have learnt
or it may lead to a job but, its mostly for fun and knowledge. Short courses are all about fun! not work, but fun!