Close Protection work is the top end of the security chain. If you gain the right experience and develop the right contacts you'll get the work. I know someone based in Hollywood, he looks after quite a few celebrities and high ranking people in the business world. Most of his work is generated by word of mouth. Where you're located is an important factor and something to think about if you're seriously thinking about a career as a CPO ( Close Protection Operative ). Attending a CPO course is a good thing and something you must do before obtaining an SIA licence.
The difficult part is getting your foot on the ladder once you've done your course and obtained an SIA licence. In the UK there are plenty of people that have done a CPO course and have a licence but there aren't enough jobs to go round. CPO work can sometimes be infrequent and clients tend to use the same CPO Operative, as trust and familiarity puts them as ease. Experience is another vital factor, a client would sooner have someone who is experienced in the field rather than someone just off a course.
Once you get a few assignments under your belt you have more chance of getting more work. While you're waiting for a break keep busy and gain experience by doing other types of security work. Security Guard, Door Supervisor, Event Security, etc. Join a security company that undertake close protection work, even if you have to start as a security guard. Show them what you can do and keep asking them for close protection work. The other alternative to try and get clients yourself. Make yourself known to large companies, get some business cards printed. It's a lot of leg work but if you get one assignment and your foot on the ladder it will be worth it.
Becoming a CPO isn't easy, I know many that have attended the course and didn't get anywhere. It's down to the individual and how determined you are. Once you make it, it's down to how well you do the job. If you're good you'll keep getting work by word of mouth, if you're below standard you won't last long.