In the olden days you will have to seek out a spiritual master to be initiated into the practice of meditation. It was considered a sacred thing only a select few will be chosen to practice.
The spiritual master will know who is fit for the practice and will decline to initiate anyone he deems not fit for the practice.
In some traditions, the student will be put to stringent tests before being accepted. In others, once accepted, the discipline is extremely strict requiring hours of practice and constant supervision by the spiritual master.
Fast forward to today, we have meditation centers offering to teach you meditation by self appointed gurus. They write books on meditation, conduct seminars, workshops and even offer online consultation through webinars.
Under pressure, even some churches have jumped on the bandwagon. They used to decry meditation as the work of the devil!
Things have changed. Meditation is no longer a sacred thing. It is a business.